 Thought experiments such as replaying the tape of life have also been considered “mental models” (see  SEP entry on thought experiments;  Nersessian 2018), and philosophers are very fond of constructing and manipulating such models to generate new insights. That microbial experimental models, which are very concrete, can potentially be compared to mental models, which are very abstract, might seem surprising at first glance. But if comparability is central to modelling practice (O’Malley &amp; Parke 2018), and if we recognize a range of model media—including mental constructs—then perhaps comparing abstract and idealized thought experiments with material models of unicellular life more often might be a fruitful philosophical approach. Now of course empirically inclined philosophers thinking about cognition or the evolution of behavior might choose instead to compare their mental models to models based on animals or plants. But just as Gause wanted the maximum reduction in extraneous complexity in order to compare basic mathematical structures with living population structures, then so might philosophers who manipulate mental structures want a stripped-down living model analogue. Whether or not philosophers feel encouraged to carry out such comparisons is not the main point of this section, however, which is primarily to note that abstract modelling efforts with mathematics and algorithms (and potentially mental constructs) can effectively be compared with microbial model systems. Such comparability then raises a whole slew of additional questions for philosophical inquiry. One of the main questions is about just how far such comparisons can be taken.