If a Realist tree falls in an Idealist forest...

This age old question has indeed puzzled me since I first heard it when I was around 10 years old. I found it fascinating to be stumped by such a simple question because it seemed to intuitively contain both a yes and no answer. 15 years later I understood why.

I have been mentoring Master students in Psychology over the past month in Philosophy of Science and Psychology. We have covered the basics of Idealism, Realism, Pragmatism, Positivism, Social Constructivism and all there is and more to these and other concepts. The most important question they've asked of me so far is probably 'Why do we have to know this?'. I give my explanation to this in a quite simple manner, we get better at research and in life in general. Then I realised something else.

Most people I have ever met, has heard the question 'If a tree falls in the forest, and no one is there to witness it, does it still make a sound? And how?'. I have never heard a satisfying answer, until I stumbled upon one myself (and I sure do hope I haven't read it somewhere, forgot, and now commit to the attribution error).

Just like Qualia, the answer depends on how you believe things exist.

If you believe that there does exist a world independent of your mind (roughly, Realism), you can define 'sound' as air compressing and decompressing, and, that this is the only necessary characteristic of 'sound' to allow its existence. Then yes. It does make a sound. We can 'know' this because the conclusion logically and necessarily follows both from the premise of our definition of sound as well as with the laws of physics.

If you however believe that there does not exist a world independent of your mind (roughly, Idealism), you can define 'sound' as sense data, and, that this is a necessary characteristic of 'sound' to allow its existence. Then no. It does not make a sound. We can 'know' this because the necessary condition following from our premise of our definition of sound is not met.

Or so I, amongst other examples, exemplify how philosophy can solve conundrums -let alone find and define logical and practical issues and weaknesses in our cognitive efforts in research and real life. Then I go on to say, but if the esteemed lecturers or the book says any different, then you should trust them (and not only for obvious reasons, but) -if philosophy teaches me anything, then it teaches me how little I can know (so if you are holding non-truths about the world -don't blame me!).