This study applied a method of assisted introspection to investigate the phenomenology of mathematical intuition arousal. The aim was to propose an essential structure for the intuitive experience of mathematics. To achieve an intersubjective comparison of different experiences, several contemporary mathematicians were interviewed in accordance with the elicitation interview method in order to collect pinpoint experiential descriptions. Data collection and analysis was then performed using steps similar to those outlined in the descriptive phenomenological method that led to a generic structure (...) that accounts for the intuition surge in the experience of mathematics which was found to have four irreducible structural moments. The interdependence of these moments shows that a perceptualist view of intuition in mathematics, as defended by Chudnoff, is relevant to the characterization of mathematical intuition. The philosophical consequences of this generic structure and its essential features are discussed in accordance with Husserl’s philosophy of ideal objects and theory of intuition. (shrink)

Paul ThagardCambridge, MA: MIT press, 2006313 pages, ISBN: 026220164X (hbk); $36.00Can human beliefs and inferences be understood as a form of coherence maximization? This question underlies much o...

In this paper I argue that the representational theory of perception, on which the world is represented as being a certain way in perceptual experience, cannot explain how there can be a genuinely epistemic connection between experience and belief. I try to show that we are positively required to deny that perceptual consciousness is contentful if we want to make its fitness for epistemic duties intelligible. (So versions of the representational theory on which experience has a merely causal purchase on (...) belief are not considered.) But my aim is not just negative. I try to defeat representationalism in such a way as to motivate a robustly presentational theory of perception. According to such a theory, perceptions are relations not between a subject and a content but between a subject and an ordinary object (such that if the relation holds at t, an appropriate subject and object must exist at t, and the object must be presented to the subject). I end by sketching an account of perceptual experience that is meant to show that, contrary to a very popular misconception, there is a way to conceive perceptual consciousness as relational and presentational (not intentional and representational) that does not succumb to the celebrated ?myth of the Given? (shrink)

Theoria, Volume 87, Issue 1, Page 87-108, February 2021.

In this paper the reader is asked to engage in some simple problem-solving in classical pure number theory and to then describe, on the basis of a series of questions, what it is like to solve the problems. In the recent philosophy of mind this “what is it like” question is one way of signaling a turn to phenomenological description. The description of what it is like to solve the problems in this paper, it is argued, leads to several morals (...) about the epistemology and ontology of classical pure mathematical practice. Instead of simply making philosophical judgments about the subject matter in advance, the exercise asks the reader to briefly engage in a mathematical practice and to then reflect on the practice. (shrink)

In On the Content and Object of Presentations, Kasimir Twardowski presents an interesting line of thought concerning the content of a presentation and its relation to the object of that presentation. This way of thinking about content is valuable for understanding phenomenal intentionality, and it should also be important for the project of “naturalizing” the mental (or at least for discovering the neural correlates of the phenomenal). According to this view, content is that by virtue of which a presentation of (...) an object presents a certain object and no other. In the cases in which an object is presented as simple, there is nothing more that can be said about the relation of content and object. It is sui generis: the relation of content to an object by virtue of which it presents that object. Further, the content of a presentation is never itself directly presented. The content can only be gotten at indirectly, as the content by which such and such object is presented. Where the presented object is complex—as is of course the normal case—a lot that is useful can be said about the structure of the content. In this paper, I lay out Twardowski's theory of the content of presentations. Since the business of content is to present its object, I briefly present the basics of Twardowski's mereology of objects. (shrink)

Edmund Husserl has argued that we can intuit essences and, moreover, that it is possible to formulate a method for intuiting essences. Husserl calls this method 'ideation'. In this paper I bring a fresh perspective to bear on these claims by illustrating them in connection with some examples from modern pure geometry. I follow Husserl in describing geometric essences as invariants through different types of free variations and I then link this to the mapping out of geometric invariants in modern (...) mathematics. This view leads naturally to different types of spatial ontologies and it can be used to shed light on Husserl's general claim that there are different ontologies in the eidetic sciences that can be systematically related to one another. The paper is rounded out with a consideration of the role of ideation in the origins of modern geometry, and with a brief discussion of the use of ideation outside of pure geometry. (shrink)

This paper provides examples in arithmetic of the account of rational intuition and evidence developed in my book After Gödel: Platonism and Rationalism in Mathematics and Logic . The paper supplements the book but can be read independently of it. It starts with some simple examples of problem-solving in arithmetic practice and proceeds to general phenomenological conditions that make such problem-solving possible. In proceeding from elementary ‘authentic’ parts of arithmetic to axiomatic formal arithmetic, the paper exhibits some elements of the (...) genetic analysis of arithmetic knowledge that is called for in Husserl’s philosophy. This issues in an elaboration on a number of Gödel’s remarks about the meaning of his incompleteness theorems for the notion of evidence in mathematics. (shrink)

This article proposes an analysis of a ritual glitch and resulting “misfire” from the standpoint of a phenomenologically informed anthropology of human interaction. Through articulating a synthesis of some of Husserl‘s insights on attention and affection with concepts and methods developed by anthropologists and other students of human interaction, a case is made for the importance of understanding the social organization of attention in ritual encounters. An analysis of a failed toast during President Obama’s 2011 State Visit to the United (...) Kingdom is used to illustrate how attention is directed toward certain participants, actions, and objects – as opposed to others. Affect-loaded empathic reactions are explained by the protracted temporal unfolding of an action whose successful conclusion – or “repair” - is ostensively and publicly delayed. (shrink)

Dan Zahavi raises doubts about the prospects for combining phenomenological and analytical approaches to the mind, based chiefly on the claim that phenomenology is a form of transcendental philosophy. I argue that there are two ways in which one might understand the claim that phenomenology is transcendental: (1) as the claim that the methods of phenomenology essentially involve addressing transcendental questions or making transcendental arguments, or (2) as the claim that phenomenology is committed to substantive theses of antirealism and the (...) like, which are sometimes thought to follow from atranscendental approach. I argue that while (1) is appropriate, it in no way leads to conflicts with analytic work in philosophy of mind. Moreover, adopting this method and practicing phenomenology in no way commits us to claims of type (2) that might be thought to conflict with common assumptions in analytic philosophy of mind. (shrink)

The article starts with a brief overview of the kinds of approaches that have been attempted for the presentation of Phenomenology’s view on the emotions. I then pass to Husserl’s unsatisfactory efforts to disclose the intentionality of emotions and their intentional correlation with values. Next, I outline the idea of a new, “normalized phenomenological” approach of emotions and values. Pleasure and pain, then, are first explored as affective feelings . In the cases examined, it is shown that, primordially, pleasure and (...) pain are recordings for our bodily and spiritual states resulting from our confrontation with beings and situations in the world. Delight and distress are, subsequently, approached as the first full-fledged emotive acts that animate or intentionally interpret pleasure and pain in specific ways. The elementary values of agreeableness and disagreeableness appear correspondingly to the latter in relation to the very pleasure or pain and to what has caused them. In other words, agreeable and disagreeable show how what we confront in the world weighs for us, what value it has for the embodied intentional consciousness, for its state and functioning as well as for its existentio-praxial possibilities in the lifeworld. (shrink)

Progressively Husserl started referring to the whole sphere of the life of intentional acts in terms of praxis. Perception, imagination, judgement, scientific consciousness, etc., are all seen as practices. What is the meaning of this move? A seemingly self-evident possibility is that intentionality is praxial, because even perception is not completely free from empty intending moments that demand fulfilment; and all fulfilment is attained by means of bodily activities that enable our senses to acquire the relevant contents. I reject this (...) approach as insufficient and misguided. I argue that perception and intentionality in general is praxial because consciousness, in all of its constituting syntheses, is or becomes organized as a practice-structure. Intentional consciousness organizes its contents according to rules so as to accomplish the evident or true givenness of its intended correlates. (shrink)

_ Source: _Volume 48, Issue 2, pp 209 - 232 In _Specters of Marx_, Derrida suggests that the most fundamental condition of phenomenality lies in the ambiguous status of the noema, defined as an intentional and non-real component of _Erlebnis_, neither “in” the world nor “in” consciousness. This “irreality” of the noematic correlate is conceived by Derrida as the origin of sense and experience. Already in his _Of Grammatology_, Derrida maintained that the difference between the appearing and the appearance, between (...) the world and the lived experience, is the condition of all other differences. Unfortunately, Derrida limits himself to a few self-evident remarks, without further elaborating.The aim of this paper is twofold: on the one hand, to contextualize Derrida’s interpretation of the noema from a theoretical and historical perspective; on the other hand, to show its effects on the early moments of Derrida’s philosophy. The result will shed light on a neglected issue in the relationship between deconstruction and phenomenology. (shrink)

: Using Judith Butler's notion that bodies are materialized via performances, "resignifying" disability involves a "democratizing contestation" of staircases because they exclude those in wheelchairs. Paleoanthropologist Maxine Sheets-Johnstone shows how consistent bipedal locomotion, together with the knowledge that we will die (upon which mutuality is based), are ingredients of our pan-hominid speciation, not contingent constructions. As axiologically important as contestation is, it forecloses the possibility of achieving a mutuality with others, that is wonderfully possible.

Using Judith Butler's notion that bodies are materialized via performances, “resig-nifying” disability involves a “democratizing contestation” of staircases because they exclude those in wheelchairs. Paleoanthropologist Maxine Sheets-Johnstone shows how consistent bipedal locomotion, together with the knowledge that we will die, are ingredients of our pan-hominid speciation, not contingent constructions. As axiologically important as contestation is, it forecloses the possibility of achieving a mutuality with others that is wonderfully possible.

Summary The present article is a partly ontological, partly Gestalt-psychological discussion of the thinkability of structures in which parts and whole are interdependent (MI). In the first section, I show that in the framework of E. Husserl’s formal part–whole ontology, the conceptualization of such an interdependence leads to (mereo)logical problems. The second section turns to and affirms the experience of this interplay between parts and whole, exemplified with B. Pinna’s recent research on meaningful Gestalt perception. In the final section, I (...) take the experienceability of MI as a justification to suggest a way of rethinking it. This entails an implementation of the process of foregrounding and backgrounding displayed by reversible figures and originally described by E. Rubin. This can avoid both an identity relation between parts and whole and their mutual exclusion as well as hierarchization due to their apparent differences. It would also guarantee the inherent dynamics of interdependence. (shrink)

In this paper I present and assess a controversy between Edmund Husserl and Heinrich Rickert on the nature of judgment, in order to bring to light the originality of Husserl's proposal concerning this important issue. In the first section I provide some context for Rickert's theory of judgment by sketching a reconstruction of nineteenth century logical theory and then proceed to introduce Rickert's view. I suggest that nineteenth century logic is characterized by a criticism of the traditional view that sees (...) categorial judgment as the essential form of judgment and the uniting and separating of ideas as sufficient for the constitution of a judgment. Hume inaugurates this criticism, but it finds its most mature expression in the work of Lotze, Brentano, and Rickert. Rickert, in particular, sees simple affirmation and negation of the transcendent value of truth as the essence of judgment. In the second section I present Husserl's criticism of Rickert. Husserl's criticism revolves around the distinction between simple judgments and the higher-order affirmative or negative stance we can adopt with respect to previously articulated simple judgments. Simple judgments register the mereological relation holding among something and one of its properties, and they do not entail an affirmative or negative stance. Their function is to constitute states of affairs drawing on concrete perceptual situations. Higher-order affirmation or negation occurs when we set out to revisit a foregoing simple judgment in order to confirm or disconfirm the veridicality of its proposed state of affairs. In the third part I suggest a diagnosis of the origin of the mistake in earlier theories. Simple judgments are easy to conflate with non-simple, higher-order judgmental stances because they have the same logical value and they cannot be seen without the aid of genuinely phenomenological reflection. In conclusion, I suggest that Husserl's analysis amounts to a vindication of categorial judgment in its traditional form ‘S is P’, which continues to maintain a phenomenological legitimacy even in the wake of Frege's canonical dismissal of subject and predicate. (shrink)

Review of Oksala's 2016 Feminist Experiences: Foucauldian and Phenomenological Investigations.

A new framework for phenomenological psychology is proposed based on Husserl’s static and genetic methods. Static phenomenology holds a eidetic psychology centred on the processes of noetic-noematic constitution and elaborates typologies and general notions about human beings in connection with the world. Genetic analysis is research into facticity, it focus on the personal history of a subject, which is constantly in the process of becoming. When the temporal dimension of consciousness is considered, the phenomenological method becomes ‘static’, as it excludes (...) the factitious dimension of self, its personal and individual history, sedimented in layers of meaning, which are in part pre-reflective, non-thematic and anonymous to the self, but which nevertheless continue to influence the experience of itself with the other and with the world. This paper aims to present some of the fundamental principals of genetic phenomenology and it’s application to existential-phenomenological psychotherapy. There are three main aspects underlying genetic-phenomenological analysis as it is being proposed: inner time-consciousness theory, the experiential self and the theory of passive geneses. (shrink)

It is sometimes said that questions of form are questions of logic or language. In his "Logical Investigations" Husserl, however, clearly distinguished formal ontology from formal grammar and formal logic. The article attempts to explain Husserl's notion of formal ontology. It investigates the relation between formal and material ontology as well as the relation between epistemic and metaphysical necessity. The article provides an interpretation of Husserl's claim that there are metaphysical necessities which are necessarily recognized by the human mind on (...) the basis of Husserl's well-known distinction between the meanings of mental acts and their objective correlates. (shrink)

Husserl’s Idea of Phenomenology is his first systematic attempt to show how phenomenology differs from natural science and in particular psychology. He does this by the phenomenological reduction. One of his achievements is to show that the formal structures of intentionality are more akin to logic than to psychology. I claim that Husserl’s argument can be made more intuitive if we consider phenomenology to be the study of truth rather than knowledge, and if we see the reduction as primarily a (...) modification in our vocabulary and discourse and not as simply a change in attitude. I briefly compare Husserl’s concept of philosophy with those of Plato and Kant. (shrink)

The paper presents a new method for generating typologies of formal-ontological relations. The guiding idea is that formal relations are those sorts of relations which hold between entities which are constituents of distinct ontologies. We provide examples of ontologies (in the spirit of Zemach’s classic “Four Ontologies” of 1970), and show how these can be used to give a rich typology of formal relations in a way which also throws light on the opposition between threeand four-dimensionalism.

Abstract That current ideals of cognition impoverish experience is a classical observation, and complaint, of the early Frankfurt School. Adorno reacts to this phenomenon in several ways, among them his conception of metaphysical experiences. Metaphysical experiences are conventionally understood as promissory notes, as metaphors for rich experiences. This article takes a different view of metaphysical experiences. It discusses them in light of Adorno's notion that objects have priority in experience and of his further remark that metaphysical experiences are constituted by (...) error. It argues that rather than promissory notes or metaphors for rich experiences, metaphysical experiences are attempts at taking things literally. (shrink)

Husserl left many unpublished drafts explaining (or trying to) his views on spatial representation and geometry, such as, particularly, those collected in the second part of Studien zur Arithmetik und Geometrie (Hua XXI), but no completely articulate work on the subject. In this paper, I put forward an interpretation of what those views might have been. Husserl, I claim, distinguished among different conceptions of space, the space of perception (constituted from sensorial data by intentionally motivated psychic functions), that of physical (...) geometry (or idealized perceptual space), the space of the mathematical science of physical nature (in which science, not only raw perception has a word) and the abstract spaces of mathematics (free creations of the mathematical mind), each of them with its peculiar geometrical structure. Perceptual space is proto-Euclidean and the space of physical geometry Euclidean, but mathematical physics, Husserl allowed, may find it convenient to represent physical space with a non-Euclidean structure. Mathematical spaces, on their turn, can be endowed, he thinks, with any geometry mathematicians may find interesting. Many other related questions are addressed here, in particular those concerning the a priori or a posteriori character of the many geometric features of perceptual space (bearing in mind that there are at least two different notions of a priori in Husserl, which we may call the conceptual and the transcendental a priori). I conclude with an overview of Weyl’s ideas on the matter, since his philosophical conceptions are often traceable back to his former master, Husserl. (shrink)

This article offers an alternative to classical hermeneutics, which focuses on discursive products and grasps meaning as the play of difference between linguistic signs. Pragmatist hermeneutics reconstructs meaning through an indefinite triangulation, which brings symbols, icons, and indices to bear on each other and considers a meaningful occasion as an embodied semiotic process. To illuminate the word-body-action nexus, the discussion identifies three basic types of signifying media: (1) the symbolic-discursive, (2) the somatic-affective, and (3) the behavioral-performative, each one marked by (...) a special relationship between signs and their objects. An argument is made that the tension between various type-signifying media is unavoidable, that the pragmatic-discursive misalignment is an ontological condition, and that bridging the gap between our discursive, affective, and behavioral outputs is at the heart of ethical life. (shrink)

The enactive approach and the skilled intentionality framework are two closely related forms of radical embodied cognition that nonetheless exhibit important differences. In this paper, I focus on a conceptual disparity regarding the normative character of action and perception. Whereas the skilled intentionality framework describes the norms of action and perception as the capacity of embodied agents to become attuned (i.e., skilled intentionality) to preestablished normative frameworks (i.e., situated normativity), the enactive approach describes the same phenomenon as the enactment of (...) norms (i.e., as sense-making) at different levels of organization that go from individual biological agents to linguistic encounters. I will argue that although both accounts accurately recognize important features of the norms of action and perception, they also have significant shortcomings. Norm-attunement accurately sees normative, ecological frameworks as the necessary set of constraints for the existence of norms at play in sociocultural bodily practices, but it fails to acknowledge the temporal and open-ended character of these norms and frameworks. Norm-enactment, by contrast, acknowledges that norms of action and perception are temporally open-ended, but fails to explicitly recognize that environmental normative frameworks are necessary for the enactment and development of all sort of norms in the interactional domain of an agent-environment system. To overcome these problems, I propose an enactive-ecological approach to norms of action and perception. This approach consists in describing norm-enactment as a result of a developmental process I call norm-development. This process describes the enactment of norms from the background of ecological, normative frameworks. These frameworks are norms enacted in the past of the interactional history of the agent-environment system that remain open to new configurations (new norms) in the present. To clarify conceptually norm-development, I appeal to Merleau-Ponty’s descriptions of norms of perception, and more particularly to his concept of spatial levels. Like the enactive approach, Merleau-Ponty recognizes that perceptual norms emerge in the interactional history of the agent-environment system, but he also posits that ecological, normative frameworks, that he calls levels, enable and constrain the emergence of perceptual norms and its development. (shrink)

Because imagination constitutes an indispensable tool of phenomenology, e.g., in understanding another author’s description, in eidetic reduction, etc., the practicability of phenomenological method and its claim to objectivity ought to be reconsidered with regard to its dependence on imagination. Auditory imagery serves to illustrate problems involved in grasping and analyzing imaginative contents – loudness in this case. Similar to phonetic segmentation and classification, phenomenologists segment and classify mental acts and contents. Just as phoneticians rely on experts’ evaluations of notations to (...) reach valid results, phenomenologists may try to develop similar agreement procedures to escape the ‘subjectivism’ of their solitary first-person approach. (shrink)

In this study, we analyse the notion of “differential heterogenesis” proposed by Deleuze and Guattari on a morphogenetic perspective. We propose a mathematical framework to envisage the emergence of singular forms from the assemblages of heterogeneous operators. In opposition to the kind of differential calculus that is usually adopted in mathematical-physical modelling, which tends to assume a homogeneous differential equation applied to an entire homogeneous region, heterogenesis allows differential constraints of qualitatively different kinds in different points of space and time. (...) These constraints can then change in time, opening the possibility for new kinds of differential dynamics and the emergence of distinct entities and forms. Formally, we show that operators with different phase spaces can be assembled on the basis of a result of Rothschild & Stein (1976. Hypoelliptic differential operators and nilpotent groups. Acta Mathematica 137. 247–320). Furthermore, operators with different dynamics can be assembled by means of a partition of the unit.After stating the concept of differential heterogenesis in terms of contemporary mathematics, we show that this construction sheds light on the constitution of the semiotic function. In fact, both the Merleau-Pontian and the Deleuzian approaches share a common conceptualisation of the semiotic function and its emergence in terms of amorphodynamics of heterogeneous assemblages with a divergent actualisation. This divergent actualisation allows the co-constitution of various expression and content planes. Finally, we show that the divergent actualisation can be interpreted as the directions of principal eigenvectors of the actualized flow. (shrink)

The present paper attempts to accomplish the following: (1) to clarify and critically discuss the phenomenology of “belief” as we find it in Husserl’s Ideas Pertaining to a Pure Phenomenology and to a Phenomenological Philosophy, First Book (1913) (henceforward, Ideas I); (2) to clarify and critically discuss the manner in which the phenomenological method treats beliefs; (3) to clarify and critically discuss the manner of belief justification as described by the phenomenological method; and (4) to argue that, just as the (...) phenomenological method can be used to validate scientific hypotheses, it can likewise be practised in our everyday worldly comportment to justify our everyday, commonsense beliefs. The paper proceeds from the idea that the phenomenological method is not the static descriptive method some make it out to be, but, rather, a living method at the service of life. The author begins with some preliminary remarks about Husserl’s concerns with unfounded or presupposed beliefs and their necessary “suspension” as dictated by the phenomenological reduction and epoche (“the method”). He then engages the text of Ideas I, especially sections 101 to 106, where Husserl presents a phenomenological conception of the character of belief. The paper concludes by treating the nature of belief justification, or “rational positing”, and puts forward the view that the phenomenological method in everyday practice can aid us in the realization of responsible epistemic conduct and, ultimately, lead toward responsible conduct towards ourselves and, hence, authentic being. Indo-Pacific Journal of Phenomenology , Volume 7, Edition 2 September 2007. (shrink)

This study explored the lived experience of security and contentment, and their absence, for latency-aged children living in shared-time parenting arrangements following their parents’ separation. A descriptive phenomenological methodology was utilized. Sixteen children living in shared-time were interviewed about their experiences of two phenomena: “feeling secure and content living in shared-time” and “not feeling secure and content living in shared-time.” The eight richest protocols were selected for analysis. The two resultant general structures and their core constituents are presented, and individual (...) variations discussed. Central to each phenomenon is the parent/s’ capacity, or incapacity, to create and sustain a physical and emotional space in which the child feels secure and held in the mind, feels the arrangements are responsive to their needs, feels free to access the “absent” parent, and experiences integration between the two parental homes. Implications for phenomenological human science research are considered, including the use of descriptive phenomenology with children. (shrink)

This paper is an attempt to clarify and assess Dennett’s opinion about the relevance of the phenomenological tradition to contemporary cognitive science, focussing on the very idea of a phenomenological investigation. Dennett can be credited with four major claims on this topic: (1) Two kinds of phenomenological investigations must be carefully distinguished: autophenomenology and heterophenomenology; (2) autophenomenology is wrong, because it fails to overcome what might be called the problem of phenomenological scepticism; (3) the phenomenological tradition mainly derived from Husserl (...) is based on an autophenomenological conception of phenomenology, and, consequently, can be of no help to contemporary cognitive science; (4) however, heterophenomenology is indispensable for obtaining an adequate theory of consciousness. In response to Dennett’s analysis, the paper develops two main counterclaims: (1) Although the traditional conception of phenomenology does indeed fit Dennett’s notion of autophenomenology, his sceptical arguments fail to rule out at least the possibility of a modified version of this traditional conception, such as the one defended in Roy et al. (Naturalizing Phenomenology, 1999); (2) the distinction between autophenomenology and heterophenomenology is at any rate misconceived, because, upon closer analysis, heterophenomenology proves to include the essential characteristics of autophenomenology. (shrink)

The experience of computer use can be productively articulated with concepts developed in the phenomenological tradition of philosophy. Building on the insights of classical phenomenologists, Ihde has advanced a sophisticated view of the ways humans relate to technology. I review and expand on his notions of “technological mediation,” “embodiment,” and “multistability,” and apply them to the experience of computer interface. In particular, I explore the experience of using a computer that fails to work properly. A revealing example is the experience (...) of a user who suddenly and unexpectedly encounters a slowly-loading webpage while using the Internet. This phenomenological framework provides an account of the ways a suddenly failing technology changes our relationships to the device, to the world, and to ourselves, and it also suggests how this experience can be usefully reconceptualized. (shrink)

The philosophical tradition of phenomenology, with its focus on human bodily perception, can be used to explore the ways scientific instrumentation shapes a user’s experience. Building on Don Ihde’s account of technological embodiment, I develop a framework of concepts for articulating the experience of image interpretation in science. These concepts can be of practical value to the analysis of scientific debates over image interpretation for the ways they draw out the relationships between the image-making processes and the rival scientific explanations (...) of image content. As a guiding example, I explore a contemporary debate over images of the surface of Mars which reveal a landmass that resembles river delta formations on Earth, and which thus has important implications for the history of Martian climate and water flow. The phenomenological framework I develop can be used to help evaluate the different interpretations on offer for these images, and to analyze the roles in this discussion played by spacecraft equipped with cameras and laser and thermal imaging devices. (shrink)