In Canions be Causes, David Johnson defends the view that abstractions can have causal force. He offers as his own example of natural kinds ecological niches, arguing that the causal force of these niches in nature is akin to the force of Aristotelian final causes. He concludes that, rooted as it is in seventeenth century mechanism, the currently-accepted model of causality which recognises only efficient causes is inadequate to the needs of contemporary science. In Natural Kinds and Ecological Niches — (...) Response to Johnson ''s Paper, Melinda Hogan offers a critique of Johnson ''s paper which, by begging the question in favor of the very sort of causality Johnson seeks to supplement, misses the epistemological implications of his idea. In this paper I will attempt to clarify and defend Johnson ''s position, pointing out some of its implications for the epistemology of science in general. (shrink)