Alistair Cameron Crombie  

"As A. C. Crombie (1950) has noted, the transition from the essentialist position to nominalism took place in philosophy and physics from the twelfth to the seventeenth centuries. It had little effect in biology until the eighteenth century, but by this time alternatives to the early strict nominalism were prevalent — conceptualism and neoplatonism. Buffon was led to espouse nominalism, not because he explicitly rejected the existence of substantial essences, but because he simply did not consider them."