Although Joseph Priestley was notorious for rejecting much of orthodox Christianity and replacing it with a materialistic Unitarianism, in another respect he was an orthodox theist of his time in that he passionately upheld the Argument from Design. The Argument from Design was the heart of his “rational religion”. He contended that natural order, especially biological order, could only be successfully explained by intentional agency. At the time, however, the Argument was coming under attack, first from David Hume, then from (...) Matthew Turner, and lastly from Erasmus Darwin. Priestley replied to each of these critics. This article surveys his replies. The three critics of the Argument contended that intelligent agency could offer only a weak explanation of natural order or that natural order is self-explanatory or that natural mechanisms can explain biological order. Priestley in turn critiqued all three contentions, arguing that the Argument is a strong explanation; that natural order cannot be self-explanatory; and that the proposed natural explanations conflict with the empirical evidence. (shrink)

Empiricism is a claim about the contents of the mind: its classic slogan is nihil est in intellectu quod non fuerit in sensu, ‘there is nothing in the mind (intellect, understanding) which is not first in the senses’. As such, it is not a claim about the fundamental nature of the world as material. I focus here on in an instance of what one might term the materialist appropriation of empiricism. One major component in the transition from a purely epistemological (...) claim about the mind and its contents, to an ontological claim about the nature of the world, is the new focus on brain-mind relations in the eighteenth century. Here I examine a Lockean trajectory as exemplified in Joseph Priestley’s 1777 Disquisitions Relating to Matter and Spirit. But Locke explicitly ruled out that his inquiry into the logic of ideas amounted to a ‘physical consideration of the mind’. What does it mean, then, for Priestley to present himself as continuing a Lockean tradition, while presenting mental processes as tightly identified with ‘an organical structure such as that of the brain’ (although he was not making a strict identity claim as we might understand it, post-Smart and Armstrong)? One issue here is that of Priestley's source of ‘empirical data’ regarding the correlation and indeed identification of mental and cerebral processes. David Hartley’s theory in his 1749 Observations on Man was, as is well known, republished in abridged form by Priestley, but he discards Hartley's 'vibratory neurophysiology' while retaining the associationist framework, although not because he disagreed with the former. Yet Hartley was at the very least, strongly agnostic about metaphysical issues (and it is difficult to study these authors while bracketing off religious considerations). One could see Locke and Hartley as articulating programs for the study of the mind which were more or less naturalistic (more strongly so in Hartley’s case) while avoiding ‘materialism’ per se; in contrast, Priestley bit the (materialist) bullet. In this paper I examine Priestley’s appropriation and reconstruction of this ‘micro-tradition’, while emphasizing its problems. (shrink)

The paper focuses on Priestley’s complex views on the essence of God in connection with his materialism, elaborated in the Disquisitions Relating to Matter and Spirit (1777/ 1782). This issue is crucial if one wishes to get a clear idea of what Priestley’s materialism amounts to; whether it is mainly a thesis about the material grounds of the human mind (“psychological materialism”), or a more far-reaching one about what kind of substances exist in the world (a version of “ontological materialism”). (...) The claim that God may be material allows for the most radical version of ontological materialism according to which everything in the world is material, without altogether denying that God exists. In fact, Priestley considers and partially defends at least three different views on the potential materiality of God: (1) an agnostic stance that is his official view, (2) materialism about God based on his own theory of matter, and (3) “gross” materialism about God. The aim of the paper is to analyze these three views, in particular concerning what kind of materialism they support and whether they can contribute to the consistent Christian materialism Priestley envisaged. (shrink)

Describing the will and the extent of its causal power over human actions, Joseph Priestley famously compared the mind to a stone, as both are subject to deterministic laws: “Though an inclination...