For whatever it&#x27;s worth, I found this explanation useful, at least when rendered visually, when first encountering this stuff.<p>But clearly the geometric viewpoint isn&#x27;t important to everybody, because the author of the post would have mentioned it if so!<p>See also, maybe: <a href="http:&#x2F;&#x2F;psychclassics.yorku.ca&#x2F;Galton&#x2F;imagery.htm" rel="nofollow">http:&#x2F;&#x2F;psychclassics.yorku.ca&#x2F;Galton&#x2F;imagery.htm</a> <a href="http:&#x2F;&#x2F;www.nytimes.com&#x2F;2015&#x2F;06&#x2F;23&#x2F;science&#x2F;aphantasia-minds-eye-blind.html?_r=0" rel="nofollow">http:&#x2F;&#x2F;www.nytimes.com&#x2F;2015&#x2F;06&#x2F;23&#x2F;science&#x2F;aphantasia-minds-e...</a> <a href="https:&#x2F;&#x2F;www.facebook.com&#x2F;notes&#x2F;blake-ross&#x2F;aphantasia-how-it-feels-to-be-blind-in-your-mind&#x2F;10156834777480504&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.facebook.com&#x2F;notes&#x2F;blake-ross&#x2F;aphantasia-how-it-...</a>