Strength
What is mental strength? Physical strength is easy enough to understand, it's a measure of how much a person can lift or push or physical strain they can endure, but mental strength is harder to characterize. Among the definitions of strength on the online OED that might apply to people, we have, "the influence or power possessed by a person," "the emotional or mental qualities necessary in dealing with difficult or distressing situations," and "a good or beneficial quality or attribute of a person." The first definition is fairly straight forward, and the last definition of which is so broad and open to interpretation, one might wonder how useful it may be. So I'm going to be talking about strength as a quality for dealing with the difficulties life presents us.
Even narrowing the definition down, its no surprise that many people have many different ideas about what mental strength really is. Is it an iron, unbending will to accomplish your goals your way no matter the obstacles life throws at you you, or is it an ability to adapt to your current circumstances to accomplish those same goals in the face of those same obstacles? One might categorize these approaches as a hard strength and a soft strength. Each of these approaches has (to use another definition of the word) its strengths and weaknesses.
In some circumstances, we face a situation in which its easy to know what the right thing to do is. While I promote a healthy amount of uncertainty and moral doubt, there are limits to everything. There are certain propositions that, no matter one's moral upbringing, we can be certain are wrong, the foremost among these being harming the innocent for no reason. And while we could debate who counts as "innocent," there is one group of people for which there should be no debate - children. Harming children should never be countenanced in any human moral system, no matter the circumstances. And in the face of such circumstances a hard, unyielding strength of character may be called for.
However, in almost any other circumstance, this hard kind of strength has many drawbacks. In more uncertain situations, we need to be open to compromise. This kind of strength is also more difficult to maintain over longer periods of time. Like other hard things, it is fragile. A person who is hard and unyielding is ultimately more likely to break in the long run.
So one of the primary benefits of a softer, more adaptable strength is that it is more sustainable over longer periods of time. In terms of enduring long-term difficult situations, bending and not breaking is essential. And in the long run, it is often easier to get what you want by being more accommodating. I also believe that change accomplished through compromise is far longer lasting than change that is imposed by the strong-willed. While such change may be accomplished quickly, it establishes a precedent that the next strong-willed person who disagrees can come along and change it just as quickly - whereas change that is achieved through compromise has broad, widespread support that is more difficult to reverse.
But many of the advantages of soft strength can also be its weaknesses. Affecting change takes longer, and that might be time that cannot be afforded. And in the process of compromise, concessions may be made that fray and weaken a person. While they may not break, they may change, and that change may not be for the better.
As with most things, balance is called for. In my opinion, a strong person is one who is at times both hard and soft, depending on the circumstances. As such, identifying strength is not always easy. However, there are several signs to look out for.
Strength is humble. A person who is actually strong has no need for self-aggrandizement. There is no surer sign that someone is mentally weak and insecure than a constant need to publicly tell other people how strong and great they are. A large part of mental strength is self-confidence, knowing who you are and what you stand for. True strength is shown, not told.
Strength accepts criticism. A person who is mentally strong has no need to be defensive in the face of public criticism. If the criticism is valid, a person needs to be strong enough to accept that they were wrong and strive to correct the issue. If the criticism is hot air, as little time and effort should be wasted on responding to it as possible. If you are worried about what other people think of you, you will rarely be strong enough to do the difficult things that may need to be done.
Strength is difficult. If a path is an easy one, little mental strength will be required. And often the most difficult things for people to do are to admit when they are wrong and to hold their friends to the same standard that they hold their opponents. A strong person recognizes their cognitive biases and attempts to treat everyone the same.
Because strength endures. If you believe you are on the correct moral path, mental strength represents your ability to stay the course. It is the faith that even when things are not going your way, someday they will because you are doing the right thing. Your example will lead others to follow your path, and once enough people do, change will come.