In a cube setting it is pretty clear that you cannot have learn cards without lessons and the lessons are far too weak to bother including in a cube. Unless you plan to make the lessons freely available without having to pick the cards then there is no chance you can run either lessons or cards that learn. To try out this new mechanic I am going to allow learn cards to find any lesson any time a bit like as if they were basic lands. If this makes learn spells too powerful or even just makes games a bit too samey I will cut them all. I might even just do that if it turns out to all be a bit too fiddly.
We have 20 lessons (2 of each colour, 5 colourless, and one hybrid mana for each pair of enemy colours) and 21 cards that can find them. None of the lessons are so exciting that you actively want to get them and as such only the learning cards that are fine enough on their own are ones that you would play. Having seen all of the cards relating to this mechanic I rate learn around the power level of investigate. Beyond that there are not so many easy comparisons. You don't need to pay 2 mana to have your extra card with learning and you effectively get to tutor up the card you most need. On the flip side the pool of cards is sufficiently weaker that you end up paying that 2 mana if/when you use the lesson. It is also the case that cards in your deck are way more powerful in their effects as well, not just in terms of value for mana. Crack that clue and find a game winning bomb card. Learn the lesson and just do something mediocre.
Lessons certainly scale nicely with looting and the like as they are much more like real cards then. They also have a nice solution vibe to them. Being able to find lands when you are in need, a removal spell when you need to answer something etc. Dealing with issues leads to good games. Drawing your own bomb cards doesn't always do that. High utility low tempo card advantage. Given how I plan to use lessons giving them a rating seems a bit odd. As stand alone cards they are basically all 0/10 but as I intend to play with them there is some merit to looking at which ones seem like they will get used and how often etc.
The five hybrid token generators will be common choices when nothing specific needs doing. They are the more generically proactive and also represent some of the best tempo options on offer. They all are still pretty low tempo plays but in the grand scheme of things they are a lot closer to curving with cube quality cards than they are to missing a beat and doing nothing. The three mana ones in particular seem like they will be some of the most cast lessons (thus giving white and black a bit more scope for learning useful things).
The colourless cards all have their place. Environmental Sciences is likely going to be the most found and played of all the lessons. Fixing and ensuring lands drops while being one of the cheapest cards you can learn are both well in its favour. Mascot Exhibition will be learned a decent amount too as it is just one of the highest in terms of raw power. It gives a decent board presence and can help push through or absorb a bunch of damage. It is however pretty late game. I suspect it will have the highest instance of being learned and not played.
Introduction to Annihilation is one of the worst lessons are far as power goes but it does answer all the problems. I imagine The Scarab God and that kind of hard to handle game winning threat will be answered with this. I suspect it will also get occasional use as a means to answer things your deck simply can't. Red decks taking out Moat etc. Powerwise it is one of the worst lessons but it does a very needed thing. When all your options are low powered cards you take the one that does the thing you most want ot need and often that will result in this heap of cack getting learned.
Expanded Anatomy is relatively cheap, has some synergy and scaling potential in most cubes, and will often be able to act immediately. It is not an exciting card by any means but I can imagine it being one of the more commonly used lessons. Introduction to Prophecy seems like it is the least useful of the colourless lessons. The cost of playing it is high and the returns are low. I might get it late if a big load of tokens or an exile removal spell didn't sort out my situation but a card in my deck did. Early on it is just such a poor tempo play with no significant value.
The ten mono coloured lessons tend to be more powerful than the ten colourless and hybrid cards we just covered. They are also narrower effects and narrower by needing exactly the one mana type. Reduce to Memory is a slight upgrade to the colourless version and is probably going to be the most commonly found lesson from learn cards in white decks. It isn't so much that it is good, just that it scales with the goodness of what your opponent is up to and with cube having all the best cards being able to exile one for 3 mana is pretty tasty. Oko getting a taste of his own medicine is a thing I expect to see thanks to this. Generous Gift is a playable card and this is comparable trading instant speed (and the ability to hit lands) for exile quality.
Academic Probation is very situational and offers no value. You might use it if desperate to buy a turn against something brutal. This will be just the ticket now and again and will result in some cool wins but should be one of the less commonly learned lessons in singleton and limited settings.
Mercurial Transformations is pretty weak. Being sorcery it is hard to use as a trick. You need to use with other things to handle problem cards or indeed to use as a pretty awful pump spell. I don't really see this ever getting taken. The colourless lessons there are do the things this can do better generally speaking.
Teachings of the Archaics is a Divination conditional on opponents having more cards than you. The draw 3 mode will rarely happen and in no way makes up for this doing nothing when you have equal or more cards. This is a low tempo card that can help pull you from behind in value or gas but cannot pull you further ahead. Power wise this is one of the better cards for the mana but it is sufficiently situational and low inherently tempo that I wouldn't expect this to be learned very often.
Confront the Past is one of the more exciting lessons in terms of power as it answers some of the scariest threats or can be an actual relevant threat of your own. It is low tempo but not shockingly so as is the case with some. It is a bit more versatile than most too so can be got speculatively which isn't the case with a lot of the options. Planeswalkers are potent in cube and this affords a nice degree of control and options in that realm.
Necrotic Fumes is just a dodgy Hero's Downfall. Exile quality is nice, sorcery speed isn't. It would be fine at that but the additional cost makes this fairly poor. It will always hurt you to use and will sometimes prohibit the use of it. Black is getting a bit more in the way of token generation in this set so perhaps that will help make this a bit more useable. You will still tend to take this over the 5 mana colourless answer if you can being that much cheaper.
Illuminate History is a massive card quality effect with a potential token kicker. Without the token the cost is extreme. You would either need the kind of heavy synergy deck you don't ever get in drafting cubes or have a pretty outrageous outlier as far as games go to find this useful as four mana card quality. If you are also getting the token then the card is a little more generally viable but not by all that much. The three mana Lorehold token lesson is often still going to be better. While this is one of the more interesting and impactful cards I cannot see it being very commonly learned at all.
Start from Scratch is terrible Abrade. A ping for 3 is pretty laughable but at least a Shatter is fine. This will get learned a bunch as a Shatter is often going to be useful and a ping is at least a thing you can use or scale. You can pretty safely grab this speculatively and not be too sad about having done so. Cheapish and interactive with a wide range of targets. One of the best lessons somehow.
Containment Breach may well be the best lesson. It answers a broad range of stuff, often stuff you have few answers for in a deck. It does so at a reasonable cost and can even generate a bit of extra value. Not quite broad enough to take as a speculative lesson if you don't know your opponents list but you can once you know they have some important targets.
Lastly we have Basic Conjuration. Find and draw dork from the top six and gain three life. Fine. This suffers a bit from being a very expensive card quality spell as well. Sure, it digs well for some action but the cost is a long way from negligible. It is likely the de facto lesson you get when green and there is no other context going on pushing you towards another lesson. It has the benefit of scaling in power along with the quality of your dorks which in cube makes it a lot more powerful that the other lessons despite being not all that. Green has a bit more mana than most colours so can handle the high cost a bit more. Six is also fairly deep and come a little closer to a tutor than just card quality. Green decks also typically have a much greater range in their cards power and effect than most other colours as a result of the ramp they tend to run. This all adds up to making this a lot lot better than Introduction to Prophecy, even if it is still a little bit underwhelming.
So there we have it, all 20 lessons. Given long enough all of them will see some action with Mercurial Transformation and Illuminate History being the two you would need to play near infinite games before they came up good. Broadly we are looking at the find a land card being a total staple and a key part of what makes learn good. After that we are looking at the removal cards, bad Shatter, bad Heros Downfall, quite bad Naturalize, bad Council's Judgement, and really bad Utter End, and just Confront the Past as the next rung of frequently taken, powerful, or desirable lessons. After that it is the token producers, Basic Conjuration, and the colourless counters buff. The remaining few cards are fairly limp and or really situational meaning we should see them least. With this in mind we could say that black is the best colour to learn in, then white, then green, then red, and lastly blue. That would be just based on the expected power and utility of the lessons they can access. It would be nice too as that is not far off the reverse order of power in my cube and might help balance things. In practice I think different colours gain more or less from lessons more as a result of their colour pie and cube archetypes. I am not sure how this pans out as there are so many variables all going on so this comes down to playtesting. Things like the removal options a colour has, the tempo they try and play at, the card quality cards they have access too etc. More importantly than all of that however is the cards you can actually learn with. The best cards in that group will effectively determine the best colour to learn with. And that is what we will look at in the next article/review thingy.