'On reading Shelley's A Defence of Poetry, the question insistently occurs why there is no similar A Defence of Science written of equal endowment.'

A person who is passionate about her/his subject is bound to praise it profoundly. The only difference might be in the medium of expression. While a poet chooses words to praise his subject, a scientist may choose an invention to express his passion. This is natural. Thus, it is so that Shelley came up with a writing piece and Faraday discovering the laws of electromagnetic induction and his discoveries led him to formulate concepts such as 'lines of force' and 'fields of force'. It is not that scientists do not defend their subject, Faraday did defend his discoveries by answering Gladstone that there was every probability of the government taxing the electricity soon. Just the medium one chooses to defend their subject matters.