Not a very nice subject. Changing views of parasites and parasitology in the twentieth century

The man in-the-street who frequently asks the question Why am I here? finds even more difficulty with the question Why are parasites here? The public's distaste for parasites (and by implication, for parasitologists!) is therefore understandable, as maybe was the feeling of early 20th century biologists that parasites were a puzzle because they did not conform to the then widely held association between evolution and progress, let alone the reason why a benevolent Creator should have created them. In mid-century, the writer, contemplating a career in parasitology was taken aback when he found that extolled contemporary biologists disdained parasites or thought little of parasitology as an intellectual Subject. These attitudes reflected a lack of appreciation of the important role of parasites in generating evolutionary novelty and speciation, also unawareness of the value of parasite life-cycle studies for formulating questions of wider significance in biology, deficiencies which were gratifyingly beginning to be remedied in the latter half of the century.