One of the oldest and perhaps the strongest superstitions that we hold onto is the duality of good and bad. Also, the law of karma is often misunderstood. It is mistaken to mean that good actions entail good effects and bad actions, bad effects. Before deciding if or not the law of karma is actually valid, a closer look at good and bad is warranted. What follows here is an abstract proof that every activity has with it both good and bad. This is supplemented with concrete instances.
The proof rests on a fundamental axiom – our capacity to effect any change is limited. Put differently, what this axiom says is that only a finite number of people get affected by one’s actions. Let the universal set of all living forms be U and the set getting affected be A. Say any particular activity X is good. The people/living forms in set A are positively affected by this activity. This leaves people/living forms in the complement set (U-A) who are not beneficiaries of this particular activity. And to the latter class of people, this apparently good activity is bad. Similar proof can be attempted with activities termed ‘bad’.
Some examples. Conventional wisdom suggests that food wastage is bad. Humans getting affected by this form the set A. This very wasted food is what microbes feed on. To the microbes (belonging to the set U-A) food wastage is actually good!! Any vegetarian fanatic would want the world to immediately turn vegan. But this very act snatches the livelihood from millions of butchers. A thief is robbing somebody of their valuables. This indeed is very bad. But this very act ensures that nobody else will be mugged during the same time. Whether the thief would have mugged anybody else or not, we do not know. But, because he is already mugging someone, he cannot simultaneously engage in another act of robbery. In economic parlance, there is an opportunity cost associated with any activity. This ensures that any activity is both a mixture of good and bad.
The law of karma is in essence the same as Newton’s third law; only discovered much, much earlier. Every action will have its reaction; i.e. every karma will bear its fruit. The question of good and bad karmas doesn’t enter here. Neither is it logically profound because there are both good and bad attached with any activity. Work backwards, the fruit (reaction) is caused by some karma (action). The law of karma constitutes the very basis of scientific enquiry. When we ask as to why the apple has fallen down, we are implicitly assuming that some karma has ‘caused’ this. It is only within this realm of cause and effect can such an enquiry exist; and the law facilitates such an enquiry.