Mendelssohn’s Philosophical Writings, published in 1761, bring the metaphysical tradition to bear on the topic of ‘sentiments’ (defined as knowledge or awareness by way of the senses). Mendelssohn offers a nuanced defence of Leibniz’s theodicy and conception of freedom, an examination of the ethics of suicide, an account of the ‘mixed sentiments’ so central to the tragic genre, a hypothesis about weakness of will, an elaboration of the main principles and types of art, a definition of sublimity and analysis of its basic forms, and, lastly, a brief tract on probability theory, aimed at rebutting Hume’s scepticism. This volume also includes the essay ‘On Evidence in Metaphysical Sciences’, selected in 1763 by the Berlin Royal Academy of Sciences over all other submitted essays, including one by Kant, as the best answer to the question of whether metaphysical sciences are capable of the same sort and degree of evidence as mathematics.