The question of the explicit is given a rather different focus in this second reading, also from On the Edge of Certainty. Here, Tallis considers the reflections on knowledge and certainty that Wittgenstein wrote during the last days of his life in 1951 in Cambridge, and which appeared as On Certainty, first published in 1969. The book is a consideration of G.E. Moore's defence of common sense, as exemplified by his assertion "I know that that's a tree". Wittgenstein was not happy with formulations of this sort; out of their usual contexts statements like "I know that that's a tree" or "I am certain that I have two hands' seem to have no sense. For Wittgenstein, doubt does not come in here: in our daily lives we make statements about our hands and we use the word "hand" without hesitation. In addition, we act, and when we act we almost always make use of our hands: we wash ourselves, including our hands, we fix things, we cook, we clean, we write, and so forth. As Wittgenstein has it: in the beginning was the deed. It is not knowledge and certainty that lie at the basis of how we use language: it is the presuppositions built into a way of life. Freedom from doubt in this context is not based on reasoning or proof. As Norman Malcolm has noted, in a lecture on the relation of language to instinctive behaviour, this freedom from doubt is too fundamental to be either "unjustified" or "justified". In fact, this way of being with language is so fundamental that there seems to be no way of describing it in language at all: it is no good calling on expressions like "knowledge", "belief", "certainty", or "acceptance", since these have their appropriate usage within specific language-games, and what Wittgenstein was trying to get at is something that lies beneath all language-games. But as he addressed this question, the ground was constantly shifting under his feet, and in the last days and hours of his conscious existence Tallis believes him to have been suspended between his own intuitions of chaos and an ordered world — the world of concepts and linguistic practice — that had no way of acknowledging what lay outside itself.