The subject of 'New Light' holds some fascination for me. And I have sought a wide spectrum of views to really understand the concept. Proverbs (4:18, I think) says the path of the righteous on gets lighter and lighter; Pastor Russel (or some very old literature)reaffirmed this inspired thought by stating that 'New Light' never contradicts 'Old Light', only that it makes things clearer. However, in view of the various total reversals in JW teaching, the 'Tacking' explanation was invented to explain the changes. In tacking, it is said, a sailor manipulates the sails and goes back and forth, right and left, while all the while making progress towards the shore or destination. I have heard others use this to explain the changes that have been made, but it doen't sound sound. Isn't it just easier to accept that mistakes have been made because humans were overzealous or jumped ahead in reading Jehovah's mind?
*Don't know if this has been discussed before; if so, kindly refer.