and biologically a new process of cognition begins with the satisfaction they create: the hypotheses whose verification ends in them are considered to be upheld, and the formulation of more general hypotheses is sought, the guessing and search for universal laws goes on. The observation statements constitute the origin and stimuli for these events that follow in time, in the sense described earlier. 

It seems to me that by means of these considerations a new and clear light is cast upon the problem of the ultimate basis of knowledge, and we see clearly how the construction of the system of knowledge takes place and what role the "confirmations" play in it. Cognition is originally a means in the service of life. In order to find his way about in his environment and to adjust his actions to events, man must be able to foresee these events to a certain extent. For this he makes use of universal statements, cognitions, and he can make use of them only in so far' as what has been predicted actually occurs. Now in science this character of cognition remains wholly unaltered; the only difference is that it no longer serves the purposes of life, is not sought because of its utility. With the confirmation of prediction the scientific goal is achieved: the joy in cognition is the joy of verification, the triumphant feeling of having guessed correctly. And it is this that the observation statements bring about. In them science as it were achieves its goal: it is for their sake that it exists. The question hidden behind the problem of the absolutely certain basis of knowledge is, as it were, that of the legitimacy of this satisfaction with which verification fills us. Have our predictions actually come true? In every single case of verification or falsification a "confirmation" answers unambiguously with a yes or a no, with joy of fulfillment or disappointment. The confirmations are final. 

Finality is a very fitting word to characterize the function of observation statements. They are an absolute end. In them the task of cognition at this point is fulfilled. That a new task begins with the pleasure in which they culminate, and with the hypotheses that they leave behind does not concern them. Science does not rest upon them but leads to them, and they indicate that it has led correctly. They are really the absolute fixed points; it gives us joy to reach them, even if we cannot stand upon them. 

VII 

In what does this fixity consist? This brings us to the question we postponed earlier: in what sense can one speak of observation statements as being "absolutely certain"? 

I should like to throw light