 Instead he restricts his investigation to the “purpose to enquire into the original, certainty, and extent of human knowledge” (Essay I.I.2). Such an investigation presupposes an acquaintance with our own minds, and thus according to Locke the most pressing task is to understand the mind or the understanding itself. And because for Locke the sole material the mind has the ability to process are ideas, the most pressing task if one wants to understand the possibility of knowledge is to give an account of “how he [the mind] comes by them [the ideas]” (Essay II.I.1). There is no need to go into the details of Locke’s conception of how the mind gets ideas and what the understanding does with them in order to arrive at knowledge. Although his description of these processes differs in some interesting ways from the model Hobbes proposes, in the end both Hobbes and Locke share the view (1) that whatever we can know depends on our having ideas which must be somehow based in sensation, (2) that there must be some external cause (Hobbes) or some source of affection (Locke) which gives rise to sensory ideas, yet (3) ultimately we are ignorant about the real constitution of these causes and these sources. What we know is the content and structure of our own ideas, although we have no reason to deny the existence of external objects and even assume that in some regards external objects resemble our ideas of them (in the case of primary qualities).