Antonyms for "presume true" can be described as doubtful, uncertain, or disbelieved. When we do not presume something to be true, we are questioning its validity or relying on evidence to confirm or deny it. We need to be careful not to jump to conclusions without sufficient evidence, making assumptions and presumptions that may not be accurate. Being skeptical, critical, or unbiased are all antonyms to presuming something to be true without evidence or proof. Therefore, we should always approach an idea or concept with an open mind, investigating and analyzing it before confirming or discrediting it.