Yet even if logic survived this onslaught, it faced another threat – this time from psychology. According to ‘psychologism’, as it came to be called, logic was not based upon universal rules, and thus it did not produce abstract irrefutable truths. As early as 1865 the English philosopher John Stuart Mill had declared that logic in fact ‘owes all its theoretical foundations to psychology’. The truths of psychology initially arose from self-observation and our personal experience of the world. This meant that the axioms upon which we base our thought must surely be no more than ‘generalisations from experience’. The law of contradiction was not a universal truth, it was simply the way human beings thought. Logic was rooted in our psychology. So what became of philosophy? Was our entire attempt to know the truth about ourselves and the world doomed?
The twenty-two-year-old Heidegger had turned to philosophy in order to reach beyond all that he found inadequate in theology. He had wished to discover a certainty in which to ground his resistance to all the bewildering and multiplying uncertainties of the modern urban technological world. But now even philosophy itself was coming to an accommodation with science and modernity. The trend was away from the lofty spirituality he sought, toward down-to-earth positivism. This attempted to eliminate all systems and remnants of metaphysics from philosophy. Only truths such as those of experience, scientific experiment, or mathematics were acceptable. All of these could be either demonstrated or proved.
The main modern philosophy that sought to resist this trend was phenomenology, whose leading exponent was the German philosopher Edmund Husserl. Early in his student days, Heidegger borrowed Husserl’s Logical Investigations from the university library. Reading this work proved nothing less than a revelation to him. He kept the book in his room for the next two years. (Evidently no one asked for it at the library.) Heidegger was so overwhelmed that he ‘read it again and again’. He even became obsessed with the physical actuality of the book itself: ‘The spell emanating from the work extended to the outer appearance of the sentence structure and the title page.’
Heidegger graduated in 1913 but continued with postgraduate studies at Freiburg. A year later Europe was plunged into a world war. This traumatic event was at first welcomed with almost universal enthusiasm. On both sides, thousands of young men rushed to volunteer. Columns of troops marching to the railway stations to embark for the front were pelted with flowers by cheering crowds – from Glasgow to Budapest, from St. Petersburg to Rome. Many, of all classes, who had sensed an emptiness in their lives, now found a meaning in emotional patriotism. But this was to be a war without glory, such as none had foreseen. Battle tactics as ancient as battle itself were used against modern weapons. Machine guns mowed down advancing lines of thousands upon thousands, gas warfare blinded and suffocated, entire resentful armies rotted in the mud of the trenches. The civilian population was kept largely oblivious of this, with life continuing as before. Meanwhile an entire era of class-stratified society, inspired by the certainties of ‘God and country’, formed by ‘a century of peace, progress, and prosperity’, was dying amidst a slaughter the like of which had never been seen before. (On the opening day of the Battle of the Somme there were almost sixty thousand casualties, a figure similar to the results when the first atomic bomb was dropped on Hiroshima forty years later. The Battle of the Somme would continue for another four and a half months.)
Heidegger was called to military service but found to have a weak heart. He was placed in the reserves and ended up back in Freiburg working as a mail censor, a cushy job which enabled him to continue with his philosophy. In 1915 he began teaching at the university. The twenty-six-year-old from the backwoods had now become a university lecturer embarking upon a respectable career, with high prospects. Though earnest and ‘spiritual’, he was also highly ambitious. In 1916 he became engaged to Elfride Petri, an independently minded economics student who came from a Prussian military family. Three months later they were married. By this time the famous Husserl had arrived as professor of philosophy at Freiburg, and Heidegger had become his assistant. Although phenomenology was hardly well known outside academic circles, it was already being seen as something more than just a new philosophy. This was a movement that might one day fill the ‘spiritual vacuum’ that many were beginning to discern at the heart of German culture. Such was Heidegger’s deep and perceptive understanding of Husserl’s phenomenology that the two quickly became close. The professor soon began looking upon his bright young assistant in recognisably paternal terms. Here perhaps was his eventual successor in the growing phenomenological movement.
Husserl was convinced that he had found the answer to ‘psychologism’ as well as to positivism’s attempt to reduce all ‘truth’ to scientific truth. It was not a matter of denying such claims but attacking them head-on. According to his analysis, such views might be true within their own realm, but they remained ultimately inadequate. Science and psychology were based upon experiments, which meant that they always remained to a certain extent inexact, unlike the precise truths of logic and mathematics. 2+2=4 precisely. There is not even a possibility that it might just be 4.000001: we know that even to a thousandth of a percent and beyond it is always correct. Compare this with the most precise measurements of the speed of light, which can now be calculated to well within a millionth of a percent. We accept the value of this constant as 186,000 miles per second, but we know that this can never be exactly correct, no matter how precise our measurements. Here Husserl was in agreement with Einstein, who maintained: ‘As far as the laws of mathematics refer to reality, they are not certain, and as far as they are certain, they do not refer to reality.’
For Husserl, the laws of mathematics were ideal, they existed a priori – that is to say, they existed before our experience, and regardless of our experience. Even if there were no human beings to experience it, two plus two would still equal four. There remained a categorical difference between these ideal laws and real laws (those we apprehend in reality). Admittedly, we first become aware of these ideal laws by experience. But a logical or mathematical law is not confirmed by any ‘feeling’ we may have when we experience it. We intuit it, and at once we realise that it is self-evident. When we see that 2+2=4, we somehow know it is true.
If psychologism was correct, this would mean that 2+2=4 would not be incontrovertible. It would simply arise from one’s personal intuition of the world. Others might intuit it differently – and we would have no grounds for refuting them.
Husserl used the example of geometry, which he considered the most absolute and incontrovertible of all mathematical knowledge. The entire edifice of geometry was built upon a foundation that consisted of such basic concepts as ‘line’, ‘distance’, ‘point’, and so forth. According to Husserl, there was certainly an actual day in prehistoric time when particular individuals must have had intuitions of these concepts. In the midst of the flow of his experience, a particular primitive human being suddenly intuited the idea of a ‘point’. Later, another understood the concept of ‘line’. But once understood, these concepts had a precise and undeniable meaning. The rest of geometry consisted simply of exploring the logical implications that arose from these basic concepts. For instance, if we have one line, it is possible to have two lines, or even three. If these three lines are joined so as to enclose a space, they will form a figure with three angles: a triangle. This is necessarily true, and could not be otherwise. It had always been true, and always would be. Geometry did not contain these truths, they were ‘already there’, simply waiting to be discovered. This was the same with all mathematics, all logic, all absolute knowledge. They somehow existed beyond reality, beyond the inexactitudes and uncertainties of everyday life. They existed in a realm of their own. There was a ‘presence’ where absolute truth existed – the only alternative would have been an ‘absence’. Such a ‘presence’ guaranteed all absolute truth by its very existence.
Husserl’s ‘presence’ bears a strong resemblance to an unseen all-seeing God, whose existence guarantees all truth. Indeed, at the outset of his career Husserl had stated that his aim was ‘to find the way to God and to a truthful life through strict philosophical scholarship’.
But