This chapter needs to begin with some qualifications. To start with, both nouns that appear in the title of this chapter are not unproblematic when applied to ancient philosophy. For the term “science”, this is because science as a technical, systematized and institutionalized activity was not, in antiquity, distinct from philosophy. What we call “science” today is an outgrowth of ancient natural philosophy, that is, theoretical research concerning the general explanatory patterns in nature to an extent inspired by actual empirical observation. In so far as we find discussions about how such activity should be carried out, what its aims are and what its structures are like, we can talk about ancient discussions about science. On the other hand, this discussion in Greek concerns epistēmē, which also simply means “knowledge”, and in this chapter we shall also touch on issues that pertain to knowledge rather than science.

A general supposition that the commentators tend to share is that human beings have a capacity to arrive at a comprehensive understanding or knowledge of reality. What this involves, how such knowledge or understanding is achieved, and to what extent it may be called “science” are questions that need to be addressed separately in the case of individual commentators. In this chapter, we shall address these questions through examples from Alexander, Themistius, Philoponus and Simplicius. We concentrate on the questions of what kind of knowledge epistēmē or science involves, how we attain such knowledge, and to what extent logic is employed in scientific or philosophical research.