For this reason it could not acquire either autonomy or the value of radical questioning: it prowled endlessly through a region where what mattered was resemblance, the strength of the imagination, nature and human nature, and the value of general and abstract ideas in short, the relations between the perception of similitude and the validity of the concept In the Classical age Locke and Linnaeus, Buffon and Hume are our evidence of this the critical question concerned the basis for resemblance and the existence of the genus.