“A merry heart doeth good like a medicine” –Proverbs 17:22 http://bartleby.com/108/20/17.html
“Ever since biology became a science at the hands of biochemists it has carefully avoided or renounced the concept of purpose as having any role in the systems observed… Only the observer may have purpose, but nothing observed is to be explained by it. This materialist article of faith has forced any study of process out of science and into the hands of engineers to whom purpose and process are the fundamental concepts in designing and understanding and optimizing machines.
…An automaton, thus, must have two explanations, one in terms of mechanism and accounted by efficient cause, the other in terms of process and accounted by final cause. Thus, to deny purpose to living creatures is foolish, it is tantamount to denying what you don’t choose to explain, a peculiar stance for a scientist. Logical computers can be built by the arrangement of switches. Analogue processors can be built by the arrangement of amplifiers. What is the problem? Every process must have a mechanism to sustain it. And this holds even for thinking about a process. The spirit has no subtle action (such as thinking abstractly) which is not accompanied by the action of devices in the brain which is part of the body.” –Jerome Y. Lettvin