Obviously, the most fundamental motive for economic activity is the preservation of human life; yet most people, we may assume, have never experienced any mental or physical pain owing to a lack of food to sustain mere existence or of clothing to keep them fairly comfortable. In other words, the typical man, though he may worry about meeting bills, and often wonder just how he is going to be able pecuniarily to do this or that, seldom, if ever, seriously considers the probability of death from starvation or exposure. If, however, he were driven to this extremity he would fight bitterly against any odds to secure the minimum of food, clothing, and shelter; for not to do so would inevitably mean death.