There are several well-hidden gestures to find and collect in Elden Ring's The Lands Between, and there are some that are far more convoluted than others. Unless you're going out of your way to explore the hidden, optional areas or backtracking for NPC quests, you'll never get your hands on some of the rarest gestures.
Erudition is among these, hidden behind a sturdy barrier of backtracking for Thops's quest and a mediocrely complicated tower rooftop jumping puzzle. Getting the item necessary for this gesture does, however, have its dark payout - as is customary for any FromSoftware game. You'll need to determine if your gesture is worth the cost of a man's fate.
Finding Thops
Thops can be found just outside of Stormveil Castle at the Church of Irith, located near the Lakeside-Facing Cliffs Site of Grace. After speaking with him, he'll tell you that he requires a Glintstone Key in order to into Raya Lucaria. You may try to give him your Glintstone Key after you find one, but unless you have two, he'll refuse to take it. Therefore, you'll need two Glintstone Keys, and the second is hidden at the end of a tower puzzle in Raya Lucaria Academy.
The Second Glintstone Key
In order to reach the second key, you'll need to defeate the Red Wolf of Radagon in the Debate Parlor. From the Debate Parlor Site of Grace, head outside into the gardens and face the crumbling staircase to the west. Climb here, dispatching the many enemies if you'd like the extra Runes, and jump over the railing to the left of the door that acts as the shortcut to Rennala's room. A sorcerer will be stationed directly behind you, so defeat them and open the shortcut door, in case you need to return later.
Continue west past the sorcerer at the top of the stairs. Jump over the railing onto the rooftops.
Here, you'll notice a few Marionettes. Continue past them to climb the ladder up onto the bridge above, where a Sorcerer with the Shard Spiral spell and several aerial Marionettes on the lamposts lie in wait to ambush you. You can ignore them and sprint past, if you wish.
You'll probably want to at least dispatch the ranged Marionette as it can strike you while climbing the ladder. Additionally, left of the ladder is Golden Rune (4) you can grab easily on your way.
Circle the building (until you're facing west) once past the sorcerer and jump onto the rooftops below. Continue jumping down toward the Marionette below, defeat it, and jump off the ledge facing west. Once you round the corner and find a semicircular rooftop patrolled by another Marionette, jump onto it. Defeat the one Marionette so it can't attack you during the minor platforming segment to come.
Enter the first window of the building in the center of this rooftop to carefully clamber on the rafters.
There's an item you can receive here in the center from the corpse, but the Glintstone Key is on the first chandelier on the southernmost side of the room. From the first rafter you climb onto, position yourself carefully, ever so slightly on the eastern side of this rafter and then step off. The Glintstone Key will await you down below.
Trading For Erudition And Using It
With your second Glintstone Key in hand, return to Thops at the Church of Irith. Give him the Glintstone Key and let him finish his dialogue in order to receive the Erudition gesture. You can then use it by opening your menu, switching out a current gesture with Erudition, and selecting it to use. From here, you can choose at this point to continue Thops's questline or walk away blissfully unaware with your new emote in hand.
If you'd like, you can use this new emote when wearing a Glintstone Helmet of any kind in order to witness a minor special event.