Brief notes on the different Grounds of Inference

We come to the consideration of vyapti or invariable concomitance between the middle term and the major term, which is the logical ground of inference.

In inference our knowledge of the sadhya (fire) as related to the paksa (hill) depends on the previous knowledge of the hetu (smoke) as connected with the paksa on the one hand and universally related to the sadhya on the other.

We infer that there is fire in the hill, because we see that there is smoke in the hill and know that smoke is always accompanied by fire. It appears, therefore, that an inference has two conditions.

The first is cognition of the hetu or middle term (smoke) in the paksa or minor term (the hill). The second is the reladon of invariable concomitance between the middle and the major terms.

That there is fire in the hill is a conclusion which we can justify only if we know that there is an invariable concomitance between the hill smoke and fire.

This relation of invariable concomitance between the hetu and the sadhya, or the middle term and the major term of inference is technically called vyapti, and is regarded as the logical ground of inference, since it guarantees the truth of the conclusion.

So the questions we are to consider now are; what is vyapti? How is vyapti known by us?

With regard to the first quesdon, we have to say that vyapd literally means the state of pervasion. It implies a correlation between two facts, of which one is pervaded (vyapya), and the other pervades (vyapaka).

A fact is said to pervade another when it always accompanies the other. A fact is said to be pervaded be another when it is always accompanied by the other.

In this sense, smoke is pervaded by fire since it is always accompanied fire, or all smoky objects are fiery. But while all smoky objects are fiery, all fiery objects are not smoky, e.g., the red-hot iron ball.

A vyapti between terms of unequal extension, such as smoke and fire, is called asamavyapti or visamavyapti. It is a relation of non-equipollent concomitance between two terms, from one of which we may infer the other, but not vice versa.

We may infer fire from smoke, but not smoke from fire. As distinguished from this, a vyapti between two terms of equal extension is called samavyapti or equipollent concomitance.

Here the vyapti holds between two terms which are co-extensive, so that we may infer either of them from the other, e.g., ‘nameable’ and ‘knowable’. Whatever is nameable is knowable, and vice versa.

For any inference, the minimum condition is some kind of vyapti between the middle and the major terms.

This satisfies the fundamental law of syllogistic inference that one of the premises must be universal now the between the middle and the major term means generally a relation of co-existence (sahacarya) between the two, e.g. ‘Wherever there is smoke, there is fire.’ Every case of co-existence.

However, is not a case of vyapti? In many instances fire may co-exist with smoke. Still there is no vyapti or universal relation between fire and smoke, since there may be fire without smoke.

The reason is that in such cases the relation of co-existence is dependent on certain conditions (upadhi) other than the terms related. Thus the presence of smoke in fire is conditioned by wet fuel (ardrendhana).

So we are to say that vyapti is that relation of co-existence between the middle and the major term which is independent of all conditions.

It is an invariable and unconditional relation of concomitance (niyata anaupadhika sambandha) between the middle and the major terms.

The second question is: how is vyapti known? How do we get a universal proposition like ‘all smoky objects are fiery’, or ‘all men are mortal’?

This is the problem of induction. For the Carvakas, who are radical empiricists, there is no problem because there is no inference as a source of true knowledge.

All the other systems of Indian philosophy which admit the validity of inference try to solve this problem in one way or the other.

The Buddhists base the knowledge of universal propositions on the principles of causality and essendal identity, which they regard as a priori and necessary principles of human thought and action.

If two things are related as cause and effect, we know that they are universally related, for there cannot be any effect without its cause.

To determine the causal relation between them, the Buddhists adopt the method of pancakarani which is as follows: (a) neither the cause nor the effect is perceived (b) the cause is perceived, (c) immediately, the effect is perceived. (d) The cause disappears (e) immediately, the effect disappears.

Similarly, if two things are essentially identical, (i.e., possess a common essence) they must be universally related. All men are animals, because animality belongs to the essence of both, and men without animality will not be men.

The Vedantins hold that vyapti or the universal proposition is the result of an induction by simple enumeration. It is derived from the uncontradicted experience of agreement in presence between two things.

When we find that two things go together or co-exist, and that there is no exception to their relation (vyabhicaradarsane sati sahacaradarsanam) we may take them as universally related.

The Naiyayikas agree with the Vedantins in holding that vyapti is established by the uncontradicted experience of the relation between two things, and not on any a priori principle like causality or essential identity.

They, however, go further than the Vedantins and supplement uncontradicted experience of the relation between two facts by tarka or indirect proof and by samanyalaksana perception.

The Nyaya method of induction or generalisation may be analysed into the following steps: First we observe that there is a relation of agreement in presence (anvaya) between two things, or that in all cases in which one is present, other also is present, e.g., wherever there is smoke, there is fire.

Secondly, we see that there is uniform agreement in absence (vyatireka) between them, e.g., wherever there is no fire, there is no smoke.

These two steps taken together correspond very well to Mill’s ‘Joint Method of Agreement’ in presence and in absence.

Thirdly, we do not observe any contrary instance in which one of them is present without the other (vyabhicaragraha). From this we may conclude that there must be a natural relation of invariable concomitance between the two things.

Still we cannot be sure if the relation in question is unconditional or free from upadhis, which a real vyapti must be. Hence the fourth step of the inductive method is elimination of upadhis or conditions on which the relation may possible be dependent (upadhinirasa).

I put on the switch and there is light; if I do not, there is no light. From this if anybody concludes that there is a vyapti or invariable relation between switching on and lighting the room, then he would commit the mistake of ignoring the upadhi or condition, vtz.

The electric current, in the presence of which alone there can be light. This upadhi, viz., electric current, must be present when there is light, but it may not be present wherever there is switching on.

So an upadhi is defined as a term which is co-extensive with the major (sadhyasamavyapta) but not with the middle term of an inference (avyaptasadhana).

Taking the stock example, when one infers the existence of smoke from fire, one relies on the conditional relation of fire to smoke.

Since fire is attended with smoke on the condition of its being fire from ‘wet fuel’ It will be seen here that the condition ‘wet fuel’ is always related to the major term ‘smoky’, but not so related to the middle term ‘fire’, as there are cases of fire without ‘wet fuel’.

Hence to eliminate the suspected conditions of an invariable relation between two things, we must make repeated observation (bhuyodarsana) of their agreement in presence and in absence under varying circumstances.

If in the course of this process we see that there is no material circumstance which is present or absent just when the major term is present or absent, we are to understand that its concomitance with the middle term is unconditional.

In this way we can exclude all the suspected conditions of a relation of invariable concomitance between the middle and the major terms and say that it is a relauon of vyapti or invariable and unconditional concomitance.

But there is still room for a sceptical doubt about the vyapti or universal proposition thus arrived at. It may be urged by a sceptic like Hume or the Carvaka that so far as our past and present experience is concerned.

There is no exception to the uniform relation of concomitance between smoke and fire. But there is no knowing whether this relation holds good in distant regions, like the planets, or will hold well in the remote future.

To end this skeptical doubt, the Naiyayikas try next to fortify the induction by tarka. The proposition ‘all smoky objects are fiery’ may be indirectly proved by a tarka like this: If this proposition is false, then it’s contradictory, ‘some smoky objects are not fiery’, must be true.

This means that there may be smoke without fire. But this supposition is contradicted by the law of universal causation, for, to say that there may be smoke without fire is just to say that there may be an effect without a cause (since fire is the only known cause of smoke).

If anyone has the obstinacy to say that sometimes there may be effects without causes, he silenced by reference to the practical contradictions (vyaghata) involved in his poison. If there can be an effect without a cause, why seek for fire to smoke your cigar or to cook our food.”

This process of indirect proof in the Nyaya may be to correspond roughly to the method of reduction ad absurdum Western logic.

Although the Naiyayikas take great pains to establish vyapti or universal proposition on the ground of the observation of particular facts, still they feel that a generalisation from particulars as mere particulars cannot give us that certainty which we claim when we lay down a general proposition like ‘allmen are mortal’.

The proposition ‘all crows are black’ is not as certain as the proposition ‘all men are mortal’. We find it less difficult to think of a crow which is not black, than to think of a man who is not mortal.

Just as a cuckoo may be black or grey and spotted, so crows may be black or dark, grey or brown. We cannot, however, seriously and honestly think of ourselves as immortal, and regulate our practical activities accordingly.

Why this difference in the sense of security of certainty? The answer that naturally suggests itself and that not unreasonably is that while there is nothing in the nature of a crow to prevent it from being grey or brown, there seems to be something in the nature of man that makes him mortal.

We say that all crows are black, not because they cannot be otherwise, but because they happen to be so, as far as we have seen.

On the other hand, we say that all men are mortal because they are men, i.e., because they possess some essential nature, manhood, which is related to mortality.

This becomes clear when we say, ‘A, B, C are mortal, not because they are A, B, C but because they are men.’

It follows from this that an inductive generalisation must be ultimately based on the knowledge of the essential nature of things, i.e., the class-essence or the universal in them.

Hence it is that the Naiya yikas finally establish an induction by samanyalaksana perception. They hold that a universal proposition like ‘all men are mortal’, or ‘all smoky objects are fiery’, must be due to the perception of the universal ‘manhood’ as related to ‘mortality’, or that of ‘smokeless’ as related to ‘fineness’.

It is only when we perceive ‘manhood as related to mortality that we can say that all men are mortal, perceive ‘manhood’ is to perceive all men so far as they are man-as- such, and not this or that man.

So we may say that the essence of induction is not an inference of the form ‘some men ire mortal; therefore, all men are mortal’.

This is not a logically valid inference, because there is an obvious illicit distribution of the subject term men.

On the other hand, induction is a process of generalization from the particulars of experience through the knowledge of the class essences or universals underlying such particulars.