Provided Eastern ideas of unity are temporarily dismissed, we can adopt an individualistic perspective and imagine there to be a distinct, if porous, division between our internal world and the world that exists outside us—wondrously, the latter is as unique to each person as is the former. We can then speak of an event’s origin as belonging to one of these two realms, and can similarly associate an event’s consequences more strongly with one realm than with the other.

The diagram below represents all four theoretical possibilities, where the dots denote event origins and the arrow-head locations indicate which realm is most strongly impacted as a result of the event’s occurrence. The downward-pointing arrow, for example, is representative of any event that both originates and primarily impacts the external world. Such an event might be a small, solid sphere of clear glass rolling off a desk and smashing on the floor. While it’s true that a witness may have been present, unless they had previously ascribed the sphere with meaning its destruction will have had little impact on their internal world as compared to how the shards now glinting on the floor have noticeably altered the external realm.

Next, the arrow pointing to the right could represent receipt of an eviction notice and the consequent internal turmoil. Finally, the upward-pointing arrow applies to all those instances of introspective brooding that trim sculptured hedges and sow seeds in the gardens of the mind.

But what of the arrow pointing to the left? It is this arrow that was the inspiration for this post.

I have on several occasions been taken by the notion that what I’m thinking can affect how my external world unfolds, which leads to questionable conclusions of the form: event X in the external realm only occurred because I was thinking earlier of Y. According to the diagram and symmetry, such instances should exist.

Imagine lying perfectly still in your bed, knowing that whether or not you hear from a particular friend the following day depends on your thoughts. This example conveniently permits the exploration of two interpretations:

1. If, the next day, your ringing phone proves to be your friend calling, you might suppose your thoughts the night prior had traveled through the æther and provoked your friend to think of calling you.

2. If, instead, the next day you receive in the mail a letter, then you have a bit more reconciliation to do with reality and your place in it, for you’ll have to grapple with the refutation of linear-time inherent in the idea that your thoughts the night prior set in motion the mailing of a letter days earlier. It might be easier to believe that rather than influencing the letter’s mailing, your thoughts determined whether it would be delivered. Perhaps if you had cogitated on other matters, the letter would’ve been lost in transit, or torn from the postman’s hand by a rabid dog. To be an especially clean solution free of complicating implications, it would be wise to make allowance for the coupling of the letter’s failed delivery with the erasure of your friend’s memory of having composed and mailed it.