Postcognition and Peripheral Mage Sight

[Redzone]

i have a question concerning the postcognition spell (Time 2). So here is the situation:
1. the character Abelaird casts postcognition to "scry" on an event that took place within the last week;
2. in such event, Bernard (an Acanthus with Time 3, Fate 2 and Prime 1) was present.

My question is: does the postcognition effect triggers Bernard's peripheral mage sight? Presuming the answer is positive, does Bernard have an opportunity to protect himself with Shield of Chronos (Time 2), or Shield of Chronos is supposed only to stop spells like Scrying?

i apologize in advance for the typos and bad grammar.

[Tessie]

My question is: does the postcognition effect triggers Bernard's peripheral mage sight?

No. Postcognition does not travel back in time to become a spell at that point. It just shows you what happened.

Presuming the answer is positive, does Bernard have an opportunity to protect himself with Shield of Chronos (Time 2), or Shield of Chronos is supposed only to stop spells like Scrying?

If Bernard had cast Shield of Chronos with a duration that covers that specific event, then that event would be protected from Postcognition.
Shield of Chronos does not protect at all against the Scrying spell because the Scrying spell does not show either the past or the future.

[Falcon777]

I would disagree with Tessie on the peripheral mage sight part. The spell does, in fact, reach back in time to show you what happened, and thus Bernard's peripheral mage sight would ping. Thus he would have the opportunity to cast Shield of Chronos.

That being said, since I don't have the book right in front of me atm, I couldn't tell you if that's the spell Bernard should want to cast or not.

[Tessie]

It's an Unveiling spell which grants information. It has no business interacting with the past.
You don't reach back in time to snap a photo, allowing the past to react to the camera flash; the past has already happened and Postcognition is basically you developing the photo negatives of history to see what happened.
In this analogy Shield of Chronos is basically the mage hiding the negatives (and potentially putting out faked ones with the Reach option), potentially hiding the events from anyone in the future taking a look.
Time travel certainly is possible with Time, but that requires other spells.

[Redzone]

thank you for your answers.
initially i was thinking just like Falco's reply, but after some consideration (and tessie's input) i think that Postcognition doesn't interact with past events; it just reveal (or unveil) such events.

[Falcon777]

It's an Unveiling spell which grants information. It has no business interacting with the past.
You don't reach back in time to snap a photo, allowing the past to react to the camera flash; the past has already happened and Postcognition is basically you developing the photo negatives of history to see what happened.
In this analogy Shield of Chronos is basically the mage hiding the negatives (and potentially putting out faked ones with the Reach option), potentially hiding the events from anyone in the future taking a look.
Time travel certainly is possible with Time, but that requires other spells.

It is also one of the few Time spells that can use Temporal sympathy because it has been explicitly called out as capable of using that. I would strongly argue that using Temporal sympathy reaches back in time, no matter what kind of spell is doing it. "Much as two subjects may have sympathetic links crossing Space marking how magically related they are, a subject has temporal sympa-thy with its own past selves, which influences magic used with a past version of an object, place, or thing as its subject." (Bolded for emphasis, underlined for double emphasis, taken from the core rule book on page 186 where it talks about Temporal sympathy). The past version is the subject of the spell using temporal sympathy.

Now, the event in question by the original poster isn't specified as to what it is. So we don't know how it would have affected the need for Temporal Sympathy. If Abelaird doesn't need Temporal sympathy to cast his postcognition, then you can maybe make an argument that postcognition in this case doesn't ping peripheral mage sight. Maybe. However, if Abelaird DOES need Temporal sympathy, then the spell explicitly is touching upon the past version of the location being viewed, which would ping peripheral mage sight. Looking at the Temporal sympathy chart, it would be easy to make a case for Strong Temporal sympathy instead of Unchanged if only because whatever Abelaird is interested in viewing has a decent chance of having done something to the place to change the sympathy. It is equally easy, lacking context, to say that the Temporal sympathy is Unchanged.

My personal take is that Postcognition would always ping peripheral mage sight because Scrying would always ping peripheral mage sight. The question in the former is "When?" whereas the latter is "Where?"

[Satchel]

Fortunately, this discussion has been had before multiple times.

My personal take is that Postcognition would always ping peripheral mage sight because Scrying would always ping peripheral mage sight. The question in the former is "When?" whereas the latter is "Where?"

The Future is Unwritten. Postcognition can't trigger a mage's Periphery because the spell hasn't been cast yet. If it could trigger the Periphery, then that would be introducing a form of meddling with the past that doesn't interact with the mechanics we have for time travel, for which the claim that it triggers the Periphery would need to point to mechanics for time travel that don't exist. Temporal Sympathy is the mitigating factor for finding information from the past with Time magic.

To draw a simple analogy to a relatively recent game involving time travel, Postcognition is putting a king in check based on its past position — nothing is being sent back in time, so history doesn't change, but since history can't change in this process the only way to stop it is to get the checking piece out of a position where it can put the king in check.

You keep Time magic from looking at a moment by casting Shield of Chronos on the subject/area and/or making sources of temporal sympathy and relevant sympathy Yantras nonviable to acquire, not by assuming that reading the Akashic Record checks a book out of the library six weeks ago.