Pertinence and Forms of Cause in Experimental Research

A bundle of isolated facts is not science any more than a heap of bricks is the wall of a house. An “ordering” of the bricks, placing them side by side, some on top of others, is essential for building a wall. Likewise, science calls for an ordering among events; that order is mostly causal in nature. When you go to the mechanic to fix a flat tire, he looks for the nail as the first step. The flat tire, the effect, is caused by the presence of a nail in its wall. Looking for cause is so ingrained in human nature that scientists, who happen to be human, cannot do otherwise.

The relation between cause and effect has variations. Firstly, we may distinguish between a necessary cause and a sufficient cause. Exposure to tubercle bacillus is necessary for someone to get infected with tuberculosis (TB), but it is not sufficient; all nurses and doctors in the TB sanitarium are not TB patients. Lack of immunity is another cause required for the infection to become active. These two necessary causes together act as sufficient for the effect. Avoidance of either one will prevent the effect. In contrast, overeating may be sufficient cause for gaining weight.

Secondly, we may distinguish a proximate (or immediate) cause from a remote cause. If A causes B, and B causes C, then we think of B as the proximate cause and A as the remote cause of C, the effect. If I slept late, missed the bus, and, thus, could not go to the theater as I planned yesterday, sleeping late is the remote cause, and missing the bus is the proximate cause. In searching for causal connection in an experimental investigation, one or the other of the above forms of cause is discernable.

Source: Srinagesh K (2005), The Principles of Experimental Research, Butterworth-Heinemann; 1st edition.