 Brown was a poet and physician as well as a philosopher, and a rather more independent thinker than Stewart, so much so, in fact, that Stewart regarded him as something of a traitor to the philosophy of Reid. Perhaps because of his medical background, Brown was sympathetic to Humean empiricism, and to a large extent endorsed both Hume's rejection of metaphysics and his associationist psychology. Brown's first book, published in 1798 at the early age of twenty, was a set of Observations on the Zoonomia of Erasmus Darwin. His premature death in 1820 meant that he published relatively little philosophy during his life time, though his Inquiry into the Relation of Cause and Effect revealed his sympathy for Hume. At the time of his death he left behind voluminous lectures that were posthumously published. In them he was critical of Reid, though on certain issues he may be said to have sided with Reid against Hume. In his most frequently quoted remark, however, which does not come from the lectures, he famously sought to diminish the distance between the two.