2.12 Why Some Truths Are Necessary

2.12 Why Some Truths Are Necessary

🇩🇪 Deutsche Version: 2.12 Warum manche Wahrheiten notwendig sind

At this point a question arises that must be clarified: where do these necessary truths come from? Are they merely products of our thinking? Or do they have a ground in reality itself?

Some philosophers hold that necessary truths are merely laws of thought. Our intellect, they say, is so constituted that it experiences certain things as necessary. In reality, however, these necessities are merely psychological quirks — they tell us nothing about the world, only about the way our brain works.

This view is called psychologism, and it is fundamentally wrong. Husserl demonstrated this once and for all in his Logische Untersuchungen (Logical Investigations) of 1900 and 1901. His argument, in simplified form, runs like this:

If the laws of logic were only psychological laws, then they would be mere regularities of our thinking — just as it is a regularity that most people grow tired in the dark. But regularities could just as well be otherwise. It would then be conceivable for other beings to have a different “logic.” “Two plus two is four” would then not be a truth, but merely a habit of our brain.

That is obviously absurd. The truth that two plus two is four does not hold because our brain functions a certain way. It holds because it is so. It holds independently of all thinking, in every possible world. Husserl writes on this point: “What is true is absolute, is ‘in itself’” true; truth is identically one, whether human beings or non-humans, angels or gods grasp it in judgment.¹

The same holds for all the basic laws of logic: they are not psychological necessities, but necessities in the things themselves. They cannot be reduced to anything else, least of all to psychological laws of thought.

The point is this: necessary truths have their ground not in our thinking, but in the things themselves — in their essence, in their so-being. The necessity that orange, by its very quality, lies between red and yellow is not a quirk of our brain. It lies in the nature of the color orange. The necessity that responsibility presupposes freedom is not a cultural convention. It lies in the nature of responsibility.

Husserl also posed the question: if evidence — that is, the inner experience of insight — were not trustworthy, could we then “still make any assertions at all and defend them rationally?”² “Without insight, no knowledge.” Without knowledge, no science. And without science, no rational debate. Whoever denies the possibility of insight destroys the very foundation on which he himself stands.

One can put it this way: there is an objective order of things. This order obtains whether we recognize it or not. And it is the task of philosophy to recognize this order — not to invent it.

---

Next section → · Back to chapter overview

Fußnoten

1. Husserl, Logische Untersuchungen (1900), Erster Theil: Prolegomena zur reinen Logik, Halle: Niemeyer, 1900, § 36. German original: „Was wahr ist, ist absolut, ist an sich“ wahr; die Wahrheit ist identisch Eine, ob sie Menschen oder Unmenschen, Engel oder Götter urteilend erfassen. ↩

2. Husserl, Logische Untersuchungen (1900), Erster Theil: Prolegomena zur reinen Logik, Halle: Niemeyer, 1900, § 6. German original: „könnten wir überhaupt noch Behauptungen aufstellen und vernünftig vertreten?” Cf. also the well-known saying: „Ohne Einsicht kein Wissen.” (“Without insight, no knowledge.“) ↩