Some words end with <ic> in the noun form. For example, <magic>. The adj. form is <magical>. But what about other words such as <history>? Etymonline lists both -ic and -ical as proper suffixes.
So, we have both <historic> and <historical> -- is there a difference in usage? What is the "specialized sense" referred to? Or are they interchangeable? If they are interchangeable, why did both develop instead of just one? The word <fantasy> results in <fantastic> but could there also be <fantastical>? I'm not about to say there is no such word, just because I am not sure it exists! But I never hear of <energetical> being used...only <energetic>. Is this a case of a word being "morphotactically possible", even if not considered typical usage? Is it like <more curious> v. <curiouser>?
I find myself wanting to say <lexicographical> or <morphological>, but should it only be <lexicographic> and <morphologic>? If I understood the reason for <historic> and <historical> I might know the answer to the rest of my questions. I would look it up in my SOED, but it won't be here until Wednesday!