At the beginning of the 20th century, the physicists Hendrik Lorentz and Albert Einstein both concluded independently that measurements of light speed would be the same for all observers. But while both arrived at the same results from their equations, Lorentz’s explanation relied on changes that take place in ‘the ether’. Because Einstein’s paper On the Electrodynamics of Moving Bodies made no reference to a mysterious, undetectable substance, his explanation was accepted as being the most likely.

Even after Einstein’s theory of special relativity had been accepted, Lorentz wasn’t willing to let go of his belief in ‘luminiferous aether’. In 1909 he wrote, “Yet, I think, something may also be claimed in favour of the form in which I have presented the theory. I cannot but regard the ether, which can be the seat of an electromagnetic field with its energy and its vibrations, as endowed with a certain degree of substantiality, however different it may be from all ordinary matter.”

It might seem ridiculous that a serious scientist, steeped in the hard-nosed practicalities of mathematics, could be so convinced of the existence of a things which is both unnecessary and unverifiable. But ether, or aether, had been widely believed to be a reasonable explanation for those physical mechanisms we had not yet explained or understood. It was just assumed that there must be something unseen and unseeable that explained the complexity of the universe.

It’s the same sort of thinking which underpins Descartes’ approach to the division of mind and matter. If mind is somehow different to other kinds of matter, what is it composed of? How does it work? Many serious thinkers have struggled mightily to show that dualism can be made to work, but all explanations ultimately require us to accept the existence of a ‘primer mover’, a homunculus who sits within our minds, directing our responses. The idea that our brains, and therefore our minds, are composed of the same matter as everything else in the universe is too appalling for some to consider. We desperately cling to dualism because then we can argue in the existence of souls and maintain a belief that we are somehow special and different to the rest of creation.

It’s easy to chuckle at the naivety of pre-20th century minds and reassure ourselves that we, in the first quarter of the 21st century, are obviously more enlightened and not prone to such fanciful gubbins. But is positing the existence of ‘understanding’ as being somehow different and superior to mere knowledge any different? Here’s where the application of Occam’s razor can prove so useful. The razor is a heuristic for thinking about competing ideas about the natural world. Essentially the principle is this: Among competing hypotheses, the one with the fewest assumptions is the most likely.

As far as I can see, consciousness is completely explained in terms of memory and knowledge. Our minds have been shaped by thousands of years of natural selection to possess various innate, instinctive capacities. Some things are, perhaps, too vital for the survival of the species not to have carved themselves into our brains. Our ability to regulate various internal physical processes, to balance, to make sense of what we see are overseen by something in our minds, but they are not conscious.

Consciousness, the ability to think, is sited in what we’ve come to call our working memory. This is where introspection occurs, and it is the only area of the mind to which we have access. We’re aware there are things we know that we’re not currently thinking about, and we can. with but a little effort, draw them into consciousness, but where do we keep these things when we’re not thinking about them? Where do they go after they have been thought about and our attention has been caught by something new? The best answer we’ve arrived at so far is to speculate that there’s another compartment in our mind which we’ve come to call long-term memory.

Plato thought of long-term memory as a vast bird-cage and our memories as birds. When we wanted to think about one of these memories we’d have to call it to us. Sometimes birds would stubbornly refuse to come, sometimes they’d appear to have escaped the aviary. Instead of this squawking, feathered mass, we’ve come to think that the birds of our memories flock together. These flocks have been named schema. It seems reasonable to suggest that our mind has an unconscious ability to store related ideas and experiences together. We might be able to exert some conscious control over this process, but it happens whether or not we will it. As our experience of our environment grows and is organised, we become increasingly self-aware, until we are able to sort our thoughts and feelings into words.

Is there an ‘ether’ that allows us to do this? In the absence of a more elegant explanation it might be reasonable to think so. Happily, David Geary’s theory of biologically primary adaptive modules of ‘folk knowledge’ and secondary modules of culturally specific knowledge allows us to suggest a less mystical way of thinking about how we learn. Our brains, it would seem, our adapted to learn some things much more easily than others. The modules of ‘folk knowledge’ are so important that they have come to be essentially human characteristics. Every human culture possesses language and has easily acquired systems for learning about the natural and the social world. These are a species-constant, universal inheritance we can trace back to the first appearance of Homo sapiens.

Where human cultures diverge, so does culturally specific, biologically secondary knowledge. Evolutionary biologist, Richard Laland says in his master work, Darwin’s Unfinished Symphony, “Humanity’s success is sometimes attributed to our cleverness, but culture is actually what makes us smart. Intelligence is not irrelevant of course, but what singles out our species is an ability to pool our insights and knowledge, and build on each other’s solutions.” Our ability to share what we know, first through spoken language and, latterly, through writing ensures we have quite remarkable access to a vast accumulation of cultural knowledge.

The magic of how we think can be reduced to something no less magnificent in its mundanity:

  1. Evolution shaped our brains to be able to learn somethings easily. The processes whereby learning is made possible are explained beautifully by Laland but are beyond the scope of this post. Suffice it to say that our genes have coevolved with our culture to accelerate and enhance this process to the point where we have a universal adaptation to learn, amongst other things, culturally specific spoken language easily.
  2. Everything we know – facts, experiences, feelings, procedures –  is stored as memories. These memories are distributed across our brains, but, for convenience, we have invented the ideas of working and long-term memory to explain how this process works. Knowledge is stored in the store house of long-term memory and drawn into working memory when we want to think about it. Everything of which we are conscious – and much of which we are not – is knowledge stored as memory. There is nothing that we can think about that is not accountable for in this way.
  3. The schematic nature of long-term memory can only be inferred, never observed directly. Like gravity, we can see its effects. We can be fairly sure that our memories are self organising, and the more information we store about a subject, the more effective this process becomes. We know that this process must be automatic because we don’t have to do anything to ensure it. More knowledge means more connections and more connects means better storage strength. Better storage strength is probably as good an explanation for understanding as you’re ever likely to get.
  4. There’s no need to invent a special category of mental ‘stuff’ or to suppose a more sophisticated form of reasoning; ‘understanding’ can be completely accounted for by the biological process of storing ever greater accumulations of knowledge as memories.

I’m not so foolish as to think this chain of reasoning provides proof. That is not the point. Each link in the chain can be falsified and, even if we cannot design experiments to test each link, we can subject my assumptions to logical analysis. Occam’s razor allows us to see which explanation contains the fewest assumptions. A simpler theory is preferable because it is more testable. If we posit that ‘understanding’ is different to knowledge, then we have to hypothesise the existence of something as yet unknown. Maybe, in time, such a thing will be discovered. But as things stand today, my explanation is, I think, the least flawed, but if anyone can simplify it further, I’ll happily admit to having been wrong.