Write a short essay, of around 800 – 1,000 words, on one of the following theories in respect of its effectiveness as a response to Descartes’ attempt to define an irrefutable system of knowledge, his method and his conclusions, particularly in respect of substance dualism: 1. Spinoza’s ‘Double-Aspect’ theory 2. Leibnitz’s ‘Monadology’ 3. Locke’s view on ‘representative realism’ and the limits of human understanding 4. Berkeley’s theory of ‘esse est percipi’ *Where you have used additional reading or other research methods, you must acknowledge all your sources. Marks will be awarded for annotation and bibliography.