A true necessary condition in a conditional statement makes the statement true (see  truth table  immediately below). In formal terms, a consequent N is a necessary condition for an antecedent S, in the conditional statement,  N if S ,  N is implied by S , or N S. In common words, we would also say . N is weaker than S  or  S cannot occur without N . For example, it is necessary to be Named, to be called Socrates. A true sufficient condition in a conditional statement ties the statement's truth to its consequent. In formal terms, an antecedent S is a sufficient condition for a consequent N, in the conditional statement, if S, then N ,  S implies N , or S N.
The Heart of Teaching: What It Means to Be a Great Teacher. What does it mean to be a great teacher? Of course credentials, knowledge, critical thinking, and all other faculties of intelligence are important. However, a great teacher should be much more than credentials, experience and intelligence.
What are the most valuable qualities of a good teacher? Good teachers are made up of a combination of hundreds of qualities that allow them to do their job effectively. There is no denying that all teachers have their own unique blend of these qualities. It is this uniqueness that ultimately makes a teacher special. Each teacher is different, but virtually every good teacher has some combination of these twenty-five most essential qualities.