I’ve had three magical mottos since I started studying magic. My first (a motto focused on aspiration, hope, and frankly embarrassing pretension) I had until I achieved Knowledge and Conversation of my HGA, at which point I changed it in order to focus on the issues that my HGA pointed out to me (duality, prejudice, self-loathing). I had that until grad school, when I started work on making my foundation secure. In some systems, this would be the work of the adeptus major and adeptus exemptus, but I don’t really belong to those systems. I changed it to focus on issues of power and fate and determination, self- and other-. I’ve had it ever since, although it long since stopped really representing me. So now I’m taking on a new motto, representing my determination to control the thing that most holds me back in my spiritual and mundane work: I am now Frater Timor Canicula Mea Est. At least, for the time being.
Most magicians who ascribe to the magical motto as a useful method tend to change theirs at significant moments of their magical practice. Why is that? It’s because it is a useful method: the motto is one of the more powerful tools of the magician, because, used well, it’s a kind of magical oath. Like all magical oaths it inevitably comes to fruition. To pick a motto that aspires to a particular thing guarantees that thing manifests — for better or worse — in some way. Whether it’s for the better or the worse depends entirely on the magician’s use of his or her own will.
The secret of the magical motto is that it represents the magician’s weakness, not strength. When Crowley went by Perdurabo, he wasn’t bragging that he “will last through.” He was pointing out that he had a tendency to give up, buckle under, be weak and doubt his own success. Saying Perdurabo was his way of saying “Yeah, I give up, fail, give in, fall down — but I won’t. I refuse to be that anymore. It’s time to be something else, something that endures.” I’m not intending to talk for Crowley; he did that plenty well himself. But it’s obvious to anyone who has had a magical motto that this is what he meant by taking on that name.
The magical motto represents a goal, not an attribute the magician already possesses. That’s its power.