What is the difference between &quot;I swear&quot; and &quot;I affirm&quot;
<p>In court oaths, there is the option to admit one of the following:</p>

<ol>
<li>I [...] swear [...] so help me God.</li>
<li>I [...] affirm [...].</li>
</ol>

<p>What is the significant difference? I am looking for code, statute, law, or perhaps a written reference to tradition.</p>

<p>An oath, which is what you make when you "swear" something, is formally speaking a promise made to God upon which you expect others to rely, and is one for of statement that can give rise to a perjury conviction.</p>

<p>An affirmation is a statement that you state is true under penalty of perjury made only to other men and women and not to God. It is preferred by those who are non-religious and by those who feel that oaths are an improper or sacrilegious act akin to taking the Lord's name in vain or idolatry.</p>

<p>Sometimes a written statement made with an affirmation is called a declaration, while a written statement made with an oath is called an affidavit, but the actual use of those words is not terribly precise.</p>

<p>Functionally, they are equivalent.</p>

<p>It is also worth noting that only certain officials (e.g. notaries, court reporters and judges) have the authority to put someone under oath, while not all affirmations require a specially authorized official to administer an oath (although many affirmations are made before such an official). If a document is called a "Declaration" it is generally affirmed rather than sworn, and is generally not notarized.</p>

<p>In common law countries, the first law allowing affirmation in court was the <a href="https://www.british-history.ac.uk/statutes-realm/vol7/p152" rel="nofollow noreferrer">Quaker Act 1695</a> . This was limited specifically to Quakers and didn't permit them to give evidence in criminal proceeedings or to serve on juries. The form of the affirmation given is:</p>

<blockquote>
  <p>I A.B. do declare in the Presence of Almighty God the Witnesse of the
  Truth of what I say.</p>
</blockquote>

<p>Quakers, and various other Christian denominations use as biblical authority for this James 5:12, amongst other passages:</p>

<blockquote>
  <p>But above all things, my brethren, swear not, neither by heaven,
  neither by the earth, neither by any other oath: but let your yea be
  yea; and your nay, nay; lest ye fall into condemnation.</p>
</blockquote>

<p>It wasn't until (often much) later the various common law countries held that an affirmation by an atheist was considered equivalent to swearing an oath.</p>

<p>A <a href="https://www.lawreform.ie/_fileupload/Reports/rOaths.htm" rel="nofollow noreferrer">long discussion</a> is available from the Irish Law Reform Commission.</p>

<p>No difference as to the legal effect.</p>

<p>The two versions exist simply to fit religious and secular persons respectively.</p>

<blockquote>
  <p>I am looking for code, statute, law, or perhaps a written reference to tradition.</p>
</blockquote>

<p>Depends on the jurisdiction, but will basically say the same everywhere where the two forms are used.</p>

rules-of-court