I don't think I have ever read anything on Leonardo that misses the essence of his achievement so completely. I echo the earlier comment that one should read Martin Kemp on the brilliant origiinality of his drawings and the coherence of his vision. Forget whether he fits into some scientific box or other- that is just being pedantic!

It is hard not to see Leonardo as the first real genius in Europe since antiquity and one can hardly suggest that he should have narrowed his skills to just painting! One has to follow him where he decides to go. At a time when the discipline of 'science' did not exist, some of his activities were important. The medieval scholastics had shown no interest in accurate observation of the natural world. Leonardo's later anatomical drawings (aided by the provision of paper) were the earliest systematic attempt to illustrate what could actually be seen and this marks a crucial moment in the development of scientific activity. Somewhere in one of his many studies of Leonardo, Martin Kemp notes that if the heart surgeons developing artificial valves had used Leonardo's drawings as a model for the design they would have got it exactly right. So he serves credit for this achievement whether it was published or not. So let's just rejoice in the quality of his mind, one which developed in the workshops of Florence not in the university.

Leonardo was the pioneer of accurate scientific observation, especially of the human body, something unknown in medieval times and absolutely crucial if advances were to be made. The fact that these drawings were not published should not exclude him from the scientific community. Quite apart from this it is hard to think of a more imaginative mind in the fifteenth century, an age of impressive humanist scholarship.