Despite the fact that Gassendi's thought developed in a variety of ways during his lifetime, his fundamental principles – a voluntarist theology, an empiricist epistemology, a nominalist or conceptualist account of universals, and an anti-essentialist metaphysics – remained constant throughout his writings. In making this statement, I disagree with Bloch's contention that Gassendi's philosophy does not constitute a system. Bloch regards the Syntagma philosophicum as “an assemblage of historical, scientific, and philosophical discussion.” He also denies that theology played any important role in Gassendi's thought, claiming instead that it was introduced only after 1641 to dissimulate the materialism of which Gassendi was growing increasingly aware. As I have argued in Chapters 2 and 3, whatever Gassendi's state of belief, the theological views upon which he drew are voluntarist and are reflected – directly and indirectly – throughout his work. Despite changes in his reactions to skepticism, despite his growing interest in natural philosophy, and despite his increasing focus on his Epicurean project, the same theological and philosophical views remained central to his thinking from the early Exercitationes paradoxicœ adversus Aristoteleos (1624) to the posthumously published Syntagma philosophicum (1658).