What Does "Total Depravity" Mean?
Total depravity should be defined as the effect of sin on every part of who we are as human beings. This means that "total" in the phrase "total depravity" is used in a quantitative sense but not a qualitative sense. Quantitatively, every part of who we are is affected by sin. Qualitatively, it is not true that we are totally sinful or another way to put it is that we are not as sinful as we could be. Thankfully, that is not the case. Thankfully, unregenerate people can do good things.
Jesus said, "You being evil know how to give good gifts to your children." Unregenerate parents can provide good homes for their children; it can happen, and it does happen. Unregenerate people can be philanthropists. Unregenerate people can show kindness during times of tragedy or crisis. So "total" is not in a qualitative sense (as bad as we could be) but a quantitative sense, every part of us is affected by sin.
Here is another distinction. Total is used in the extensive sense; it extends to every part of us. It does not mean in an intensive sense; we are not as bad as we could be. Extensively but not intensively. This doctrine means that we are affected by sin in every part.