So You Think Humans Can’t Know Objective Reality

Maarten van Doorn
Aug 6, 2018 · 5 min read

If there is one topic to which most philosophical — ‘deep’ — conversations I have with friends turn to, it’s the question of whether we — humans — can know reality as it is in itself.

For example, many people have come across the idea that ‘the observer affects the observed’.

That sounds catchy, but what does it mean?

Something like this: in trying to figure out what is true about the world, we cannot get completely ‘outside’ ourselves.

First, when observing things, what we observe will always be partially determined by the fact that the observer is a human being.

Second, we cannot check our beliefs about what the world is like directly against reality itself, but only against other beliefs about reality that we already accept as true.

If that’s so, then the question of whether we can know how anything is independent of us, whether we can have objective knowledge of the real world, looms large.

So let’s think about the idea of ‘knowing reality’.

Mind the gap

Let’s also assume that the world appears to us in a certain way and that these appearances result from our interaction with the world.

This gives rise to the oldest problem in philosophy:

We believe that the world is a certain way because the world appears to us in a certain way.

But that means that there’s a gap!

There’s a gap between (1) the grounds of our beliefs — appearances — and (2) the content of our beliefs — how the world really is, beyond appearances.

Our beliefs are based on appearances but are supposed to be about something — reality — that transcends appearances.

That sounds problematic.

It’s also not easy to solve.

Whenever we try to step outside of ourselves, something will have to stay behind the lens.

After all, we can never abandon our own point of view.

Something in us will always influence the resulting picture.

What can we know?

At this point in the conversation, most people see the difficulty and retreat by reinterpreting the content of these beliefs in terms of their grounds.

This sounds more complicated than it is.

If our beliefs are based on how the world seems to us, then, to make the diagnosed gap disappear, we reformulate them to be about how the world seems to us, and not about how the world is in itself.

On this way of thinking, the most we can hope for is a complete understanding of how we work and therefore a complete understanding of why we think that the world is such-and-such, but we can’t say something about how the world really is:

“It has been generally granted without detriment to the actual existence of external things, that many of their predicates may be said to belong not to the things in themselves, but to their appearances, and to have no proper existence outside our representation. Heat, color, and taste, for instance, are [such secondary qualities]. Now, if I go farther, and for weighty reasons rank as mere appearances the remaining qualities of bodies also, which are called primary, such as extension, place, and in general space, with all that which belongs to it (impenetrability or materiality, space, etc.) — no one in the least can adduce the reason of its being inadmissible.” — Immanuel Kant (1783)

Kant’s position is that we can conceive of things only as they appear to us and never as they are in themselves. How things are in themselves is out of the reach of our thought.

Not just secondary qualities are subjective, but the primary ones are as well. They are both mere appearances that are located in the mind of an observer.

We were striving for objective reality, but, alas, our pursuit can only be an exploration of our own minds.

Why does the world appear to us as it does? Partly because it is like it is!

So we can only know things as how they appear to us?

That sounds disappointing.

More importantly, it also sounds mistaken.

Appearances are partly determined by the observer — true — but, for the other part, they are determined by what is observed!

Objective reality is partially responsible for why appearances are as they are.

It works both ways: appearances are a consequence of the relation between reality and our minds.

By knowing (1) what we are like and (2) why the world appears to us as it does, we can deduce (3) what the world is like. To get beyond appearances we should ask what the world must be like from no point of view to appear to us as it does.

There is something underlying the appearances and if we understand how that underlying thing interacts with our minds to generate the appearance, we can understand the underlying thing in itself.

For example, however far up we escalate in the series of “appearances” of things being extended, the “real” extension of things in themselves will keep one step ahead and recur in the explanation of those appearances:

“We can’t explain the the fact that things look spatially extended except in terms of their being extended. And we can’t explain the fact that that explanation seems true except again in terms of things being extended, their extension affecting us perceptually in certain ways, and the existence of that relation affecting the results of our investigation into the causes of our perceptual impressions of extension. And so on.” — Thomas Nagel (1986)

Still, we’re probably not taking it all in

It’s not likely that we can know things only as they appear to us. Reality appears to us naturally in certain ways, and with the help of reasoning and controlled observation, we can form hypotheses about the objective reality underlying those appearances.

Having said that, it’s also unlikely that the entire world can be identified with the world as it appears to us because it probably includes things we can’t perceive.

What we can understand depends not only on how things are but also on how we are and we can’t get completely outside ourselves. Therefore, our capacity for understanding what there is may be incomplete.

For example, humans are unable to perceive infrared light waves.

When we look at the world, it might be inevitable that something will stay behind in the lens. That does not mean that what’s observed is a complete product of what stays behind. Yet, it does mean that there might be things which the lens doesn’t register.

So can we know the objective reality?

Yes, but not the complete one.

There’s more to that

The Understanding Project

Applying insights from cognitive science and social epistemology to everyday opinion-forming

Thanks to Nick Wignall

Maarten van Doorn

Written by

PhD philosophy. Essays about why we believe what we do, how societies come to a public understanding about truth, and how we might do better (crazy times)

The Understanding Project

Essays about why we believe what we do, how post-truth societies come to a public understanding about truth, and how we might do better.

Maarten van Doorn

Written by

PhD philosophy. Essays about why we believe what we do, how societies come to a public understanding about truth, and how we might do better (crazy times)

The Understanding Project

Essays about why we believe what we do, how post-truth societies come to a public understanding about truth, and how we might do better.

Medium is an open platform where 170 million readers come to find insightful and dynamic thinking. Here, expert and undiscovered voices alike dive into the heart of any topic and bring new ideas to the surface. Learn more

Follow the writers, publications, and topics that matter to you, and you’ll see them on your homepage and in your inbox. Explore

If you have a story to tell, knowledge to share, or a perspective to offer — welcome home. It’s easy and free to post your thinking on any topic. Write on Medium

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store