 Things are different when it comes to epistemological grounds for idealism. It seems to be very difficult to connect Descartes’ and Spinoza’s views concerning knowledge with conceptions according to which knowledge has something to do with a cognizing subject actively contributing to the constitution of the object of knowledge. This is so because both Descartes and Spinoza think of cognition as a result of a process in which we become aware of what really is the case independently of us both with respect to the nature of objects and with respect to their conceptual and material relations. Descartes and Spinoza take cognition to be a process of grasping clear and distinct ideas of what is the true character of existing things rather than a process of contributing to the formation of their nature. According to Descartes the sources of our knowledge of things are our abilities to have intuitions of the simple nature of things and to draw conclusions from these intuitions via deduction (Rules for the Direction of the Mind III, 4 ff.). For him the cognitive procedure is a process of discovery (see Discourse on the Method, Part 6, 6) of what already is out there as the real nature of things created by God by finding out the clear and distinct ideas we can have of them (Discourse, Part 4, 3 and 7). In a similar vein Spinoza thinks of knowledge as an activity that in its highest form as intuitive (or third genus of) cognition leads to an adequate insight into the essence of things (Ethics II, Proposition XL, Scholium II, and Ethics V, Propositions XXV–XXVIII), an insight that gives rise to general concepts (notiones communes) on which ratiocinationes, i.e., the processes of inference and deduction, are based (Ethics II, Proposition XL, Scholium I) the results of which provide the second genus of cognition (ratio). Thus the problem for both Descartes and Spinoza is not so much that of the epistemologically motivated idealist, i.e., to uncover what we contribute through our cognitive faculties to our conception of an object, rather their problem is to determine how it comes that we very often have a distorted view of what there is and are accordingly led to misguided beliefs and errors. Given what they take to be a basic fact that God has endowed us with the capacity to know the truth (albeit within certain limits), i.e., to know to a certain degree how or what things really are, this interest in the possibility of error makes perfectly good sense (Meditations IV, 3–17; Principles of Philosophy I, 70–72; Ethics II, Proposition 49, Scholium).