There are different approaches to classroom teaching, ranging from lecturing, which is highly structured, and controlled and directed by the instructor to other styles that are more open-ended and student-centered, hence putting more emphasis on the role and participation of the student body. My own approach is somewhere in the middle.
I think too much structure tends to make a class (or even a work of art, J. S. Bach excepted) rather dull by stifling creativity and spontaneity. Spontaneity is a necessary ingredient for teaching (or pretty much anything) as it allows to take a slight detour from a given lesson plan and to incorporate and address the particular needs of a situation or of the students themselves. Many a time I had to adjust my plan because students either lacked the background or were already proficient (though the latter happens less frequently than the former).
Spontaneity allows for dealing with such situations and not feeling stressed or overwhelmed by those adjustments. In all of this, it may also help to add a healthy dose of humor suited to the context since it will more likely engage or draw in students to the given material. However, spontaneity merely on its own will lack direction and if you stray too much from the plan, you might end up getting lost.
So the best approach in my view would be what I call “framed spontaneity.” This involves a necessary and at least rudimentary structure of what ought to be covered in a class (content and learning objectives), while at the same time leaving enough space and time to readjust it as one goes along (to further sharpen the students' skills). Such a style suits best those who already have some experience in teaching and who are confident enough to handle situations that do not have nor elicit clear-cut responses, i.e. arts and humanities mainly.
In addition, such a style is also student-centered, at least to a degree. An example would be a discussion on a topic, which is at times gently guided by the instructor, but it is for a large part open to individual responses, thoughts, questions or concerns of the students. At this point, the discussions like any other in our ordinary lives, can go in different directions and as long as it does not stray too far from the topic, it can be helpful and enlightening for all involved.
I have recently come upon a great book full of resources that are convenient for such a teaching style. It is a host of philosophical scenarios compiled in the book The Philosophy Shop with entries mainly provided by members of The Philosophy Foundation. The scenarios are ranged and organized according to different fields and topics within philosophy (metaphysics, epistemology, ethics, language and meaning to name some of the major categories), and they are often presented as questions, puzzles or riddles that can lead to wider discussions.
To give a tangible example, let us look at “Immy's Box” by Peter Worley (who is also the book's editor). The starting premise is that Immy has a box that he wants to empty. So he takes out all his “bits and bobs” (whatever that may mean) and this can be demonstrated with props for special effect.
Question 1 is then whether the box is empty. Yes? But can there be anything else in it? Is empty the same as nothing? Can the box be full of nothing? And my favorite proposed question: Is the inside of the box inside the box?
This situation and the following questions are there to get those creative juices flowing. I love how a reasonably simple and mundane example can take increasingly complex and philosophically deep proportions. For example, even if Immy manages to remove finger prints, germs or atoms, can the box ever be “finally completely and utterly empty”?
In other words, is there something that can never be removed? We could talk about a vacuum as “space entirely devoid of matter,” but can we also remove space itself? And if we removed space, can we also take away time? Does the box exist in time?
All of this can lead to discussions or at least the introduction of Kant's a priori perception of space and time as well as Einstein's spacetime curvature. In other words, the discussion can go in a wide array of directions and can lead to the sharpening of critical thinking skills and increase the students' understanding of important philosophical questions and concepts.
To return to my previous point of framed spontaneity, one can see that these exercises are a little like a game of chess. They will never be the same depending on the moves and input of one's students. Either way, it engages students and can end up enriching their knowledge, while hopefully also teaching the teacher a few things along the way.
Especially in philosophy, the need to maintain absolute control or to direct the discussions to reach predefined answers ought to be generally avoided by the instructor. In fact, as in most cases of philosophy, it is less about the answers one gets but the method one uses for getting there. It is a practice of skills, such as critical thinking and asking relevant questions and responding to them logically and rationally. It is an ongoing debate because it incites and invites discussions on topics that make you think and wonder about life's mysteries.
This is one of many examples that are food for philosophical thought. It is its universal aspect and application that can engage the young and old alike in a playful manner; in fact, this resourceful book furnishes the necessary ingredients and concoctions to come up with a delicious meal for mind and soul.