I examine the views of Thomas Reid with respect to a certain version of the problem of induction: Why are inductions using natural kinds successful, and what justifies them? I argue that while both Reid holds a kind of conventionalist view about natural kinds, this conventionalism has a realistic component which allows him to answer both questions.

Priority monism is the doctrine that there is only one basic object. Priority monists often take this to be a metaphysically necessary thesis. I explore the consequences of modalizing the priority monist thesis. I argue that, modulo some assumptions, the modalized thesis entails the necessary existence of the actual cosmos. I further argue that, if the modalized thesis is true, and the actual cosmos necessarily exists, then the only possible concrete objects are the actually existing ones.

I examine the (mediated) correspondence between Spinoza and Robert Boyle concerning the latter's account of fluidity and his experiments on reconstitution of niter in the light of the epistemology and doctrine of method contained in the Treatise on the Emendation of the Intellect. I argue that both the Treatise and the correspondence reveal that, for Spinoza, the proper method of science is not experimental and that he accepted a powerful underdetermination thesis. I argue that, in contrast to modern versions, Spinoza's form of naturalism was a highly rationalist and antiempirical one. I conclude with a brief account of the value of experience and experimentation for Spinoza's scientific method.