Beyond sight and touch: indelible realities

Much of the language of our cultural lives assumes the existence of realities which we cannot see or touch. Mathematical rules, such as the principles of addition or subtraction, are examples of such unseen realities. But so are very many further concepts - such as nature or beauty. You can see and touch instances of nature or beauty, but you can't touch nature or beauty themselves. These concepts endure beyond the particular examples. This short book discusses, in a non-academic way, vario...