The Law: The first law of kenpo states that when your opponent charges straight in and attacks, you should use your feet to move your body along a circular path. You should also consider moving your arms in a circular pattern to deflect the oncoming force.
When your opponent attacks you in a circular fashion, however, you should respond with a fast linear attack —along a straight line from your weapon to his target. Just as the circle can overcome the line, the line can overcome the circle.
Grey Commentary: I think Circle and Line makes some sense from the most basic of positions. If the opponent steps in with a jab roll over the lead hand to cover the face shuffle step around to their side and then follow with a jab to the temple or a body shot or even a side kick the options are near limitless. That being said there may be instances where such a tactic is not the wisest option where I do not want to count them circling with a linear strike and then be inside their reach and instead circle around with them to maintain a fix on their position possibly circling with them will also allow me a position near an exit to allow me to escape in a street scenario or I may just not want to get close to them by going with the linear attack. Always have options.