Sound & Unsound Mind

Sound & Unsound Mind


When it comes to writing a Last Will and Testament or Codicil within England or Wales there is a legal requirement that at the time of making the will the testator / testatrix should be of “sound mind”.  A will would be invalid if the person who wrote it was of unsound mind at the time of executing the will.  The idea of a sound mind isn’t there to be awkward or making rules for the sake of making rules, its premise is there to protect vulnerable people. 

One of the ways in which it protects a person is from themselves.  A person who is obviously not of sound mind often may not even realise that they aren’t.  Such people are capable of accidentally forming detrimental choices without even realising what they are doing.  They would if they realised; dread making such decisions as they would likely run counter to their true well minded selves. 

A second way in which it protects them is from others who might use their frailty of mind to exert unwarranted control over them to push or manipulate them into creating an English or Welsh Last Will and Testament that favours them.  Such coercion by others would fall under the category of Undue Influence, which legally would not be considered acceptable.  However; with the person being of unsound mind this would create cause for their English or Welsh Will to become automatically invalidated and as such cause any attempt of undue influence upon that person to be pointless by default.        

A third way in which it protects the vulnerable would be that of the rightful heirs.  The heirs would obviously be at risk of losing out purely on the basis that acts and thoughts of madness by a person not of sound mind could wrongly render them being cut out or forgotten about within that persons’ Last Will and Testament.  The law for England and Wales therefore provides the means to allow these unsound actions to be rectified.                                                    

As furtherance to the idea of protecting the vulnerable, solicitors within England & Wales have a professional duty of care to reject creating a Last Will and Testament for someone who is not of sound mind. 


Since in England & Wales having a sound mind is a legal requirement it makes sense to understand what is via the Mental Capacity Act classed as legally being of sound mind or an unsound mind:


Sound Mind    

The person intending on creating a Last Will and Testament should be able to:     

1.  Understand that they are drafting a Last Will & Testament.      

2.  Know the consequence of their actions when making a will and be fully aware of all the implications involved. 

Comprehend the disadvantages of incompetently producing a Last Will and Testament.   

3.  Comprehend the magnitude of their entire estate and its wealth.       

4.  Allocate their estate in a sane and rational manner.

5.  Understand and recognize who they are passing their worldly possessions on to.    

6.  Understand the mode under which they are passing on their life’s estate.

7.  Discern which people would have a natural claim to some of their estate.       

8.  Comprehend the character of the legislation pertaining to a Last Will and Testament and its implications.   

9.   Weigh up the specific facts which correlate to any choices that they are making.     

10.  Understand the details that go into producing the facts that go behind making their decisions.


In summation, a person of sound mind means that the person writing the Will is free from any poor condition of mind that impairs their judgement or understanding of what they are doing. 


Unsound Mind

A mentally unsound person would be someone whom:      

1.      Has no idea what they are doing; least of all, that they may be engaging in a legal document.

2.      Unable to grasp the consequences of anything they write within their Last Will.

3.      Are unable to comprehend that there are potential disadvantages of badly producing a Last Will and Testament.

4.      Suffers an illness of the mind that taints their normal affections.

5.      Have lost their sense of right and wrong.

6.      Their decisions and actions are alien to their natural behaviour.

7.      Suffers insane delusions.

8.      Discards their estate in an irrational insane manner.

9.      Has lost the ability to retain facts sufficiently long enough to make rational decisions.


In summation, a person of unsound mind means that the person writing the Will suffers from a poor condition of mind which impairs their judgement and/or understanding of what they are doing. 


People that could come under this bracket would be:                                                                                 


  1. Those born with extreme learning disabilities.      
  2. Anyone who has suffered extensive brain damage.               
  3. Anyone with brain deteriorating diseases such as:

Alzheimer’s disease,

Progressive supranuclear palsy, 

Huntington’s disease, 

Senile dementia,

Creutzfeldt-Jakob disease or

Any other not mentioned in the above.      

  1. In patients of a psychiatric hospital.      
  2. Those who have been sectioned via the Mental Health Act.               
  3. Anyone who has been declared by the courts as criminally insane.             
  4. Those with serious tumours in the brain.        
  5. Someone taking recognised psychiatric medication.        
  6. Someone who has dispensed a power of attorney to another due to a decline in their mental wellbeing.        
  7. Those who are suffering from paranoia or other delusions.     
  8. Those with serious alcohol or other drug addictions


Reflecting over the lists above, in some of these cases the dividing line between being or not being of sound mind is not always clear cut as there are varying levels of mental illness or disorders which can make the distinction between sane enough or not sane to write a Last Will and Testament difficult sometimes to establish.


Should you be troubled by any of the above conditions or any other not listed then these impairments may well place your mental well-being into question.  For an English or Welsh Last Will and Testament to be official it is vital that the person making it is considered mentally competent; if found not to be then it could be made null and void by the courts. 

To strengthen and uphold the validity of your English or Welsh Last Will and Testament there are steps that can be taken.


Undue Influence
Choosing The Right Person To Be Executor.
Why Have Multiple Executors?
Appointing An Executor.
Rules Surrounding Guardianship
Selecting Your Guardian
Automatic Guardianship
Appointing A Guardian
Parental Responsibility
Changing Guardianship
Money For Child And Guardian