"There is no magic without sacrifice." Some traditions use this aphorism when they are teaching newcomers or first level students about magical practice. From what we have seen, many don't. It is common when the subject of sacrifice comes up in workshops or classes that the teacher or leader will talk a little bit about ancient practices of offering sacrifices to gain favor from or appease deities. Sometimes they may mention that modern traditions like Santeria sacrifice animals for particular occasions. Then they sum up the discussion with, "We don't believe this is necessary" or some similar pronouncement. In most situations Wiccans especially, but also many other neopagans, will emphasize that they do not practice animal (or human) sacrifice to placate the real or imagined fears of those in attendance that stem from misplaced claims by fundamentalist pseudo-Christians that Witches or neopagans engage in these practices.
Unfortunately this is where the conversation often ends and the class or workshop is deprived of an opportunity to enter into a substantial discussion about sacrifice.
Obviously, killing animals or humans to placate one or more deities, or to gain their favor for a good harvest or whatever is sacrifice. But this is a very narrow view. Sacrifice takes many forms, and it is necessary. Indeed, it is inevitable in any spiritual practice.
We are all familiar with the statement that you only get out of something what you put into it. This is a basic formula for sacrifice. On a fundamental level, the energy you put into your intention for magical work is part of the sacrifice you give to it. This includes energy you burn in thinking about the work, planning it, getting the components you will need for it together and the time you put into all of that. It includes the meetings and/or discussions you have with the people you may be working with, and any rehearsals or walk-throughs, trips to the ritual site and whatever you do to prepare it for your work. It includes the discipline that is required to do all of this, as well as any activities you surrender in order to carry it to completion.
Then there is the ritual and the work itself. Ritual is the culmination of all of those things mentioned above. It is the expression and the manifestation of your intention, and it is the lens that focuses the energies and intentions of all of the participants to complete the work. All of that is sacrifice, and so the ritual (any ritual) is a sacrifice.
Now let us consider the circle. Regardless of the details of how the circle is cast or the content of the ensuing ritual, the circle itself is rich in meaning. Most neopagans say the circle is a "place between the worlds." It is a magical, sacred space where other dimensions and levels of reality become accessible, where spirits, guides and esoteric energies are met and utilized in a cooperative effort for skrying, journeying, divination, celebration or magical work.
The circle is much more than just a boundary that defines and contains prescribed space for ritual. It is also a door, a vehicle, a tesseract and a world onto itself. It is a place where, for ritual purposes at least, our usual notions of space, time and causality are suspended.
In shamanic terms the circle is a nexus from which one may journey to the upper or lower worlds. Most shamanic journeys begin with a descent into the underworld. From there one might proceed to the upper worlds, but typically the underworld is where one makes contact with one's totems, animal or spirit guides. These spirit allies act as partners, advisers, psychopomps, protectors and guides, and it is almost always considered foolish to journey without them.
In Craft terms, in addition to all of this, the circle is where we meet more directly with the five traditional Mysteries – birth, growth, decline, death and rebirth. In other words, it is the womb and the tomb, which of course is the womb of Mother Earth.
The life/death and change/rebirth aspects of the circle are also representative of the cauldron of the Crone. The cauldron is where creation begins and ends. Everything come from the cauldron, and everything eventually returns to it. Whatever goes into the cauldron gets transformed or transmuted before it is reborn.
This is what happens in ritual. Every time we cast a circle or enter one we do so with the intention of causing change, not just in something else, but in ourselves as well. Even something as simple as charging a spell to help a friend get a job or a raise changes us, for we are giving of ourselves for the cause, and that contributes to our growth. If we come out of a circle unchanged we have done nothing.
This leads us to the (to some) startling realization that whenever we enter a circle we are the sacrifice. To be changed, a new part of us must be created and another part of us must die. We have to become less so we can become more.
In fact, we have been sacrificing ourselves, our energy and time and perhaps money and social activities, all the while that we have been preparing for the ritual. But the circle is where we manifest the ritual. In entering the circle to do that we put all of that energy, time, money and life-force on the figurative altar. We put it, and ourselves, on the line as a sacrifice, an offering, not to any deities, but to the work at hand, and to life.