To Kill or Not to Kill That is the Question

Friday 26th September 2014

Part 1 – The Value of Life

We all do it, we all kill bugs, but what are the ethics of doing so.

The famous arachnophobe Charlie Brooker wrote eloquently about his hatred of spiders, he said “please note I'm suggesting the use of lethal force as a default. None of this fannying around with pint glasses and sheets of paper and "putting him outside". He'll just crawl in again, stupid. If a murderer climbed through your window you wouldn't just "put him in the garden". You wouldn't rest until you saw his brains sloshed up the wall. It's the same with spiders. If it's not been reduced to a gritty, twitching smear, it's not been dealt with at all.” Killing bugs - right or wrong?

Is it ethically right that due to a wholly irrational fear and simply for the purpose of reducing the anxiety levels of one human individual many other individuals should be murdered?

Now the observant will notice that in fact we are talking about spiders and bugs, not about humans and therefore we can chose to apply different sets of ethical rules to how we treat a wasp or a butterfly or a jellyfish or a human. 

One could try to determine a formula to calculate a value for the life of an animal.  By observation the value would probably correlate positively with factors such as:–

  • • how closely related to a human is it,
  • • how similar are its mental functions to those of humans,
  • • how much does it behave like a human (even just a little bit helps),
  • • how much does it feel pain (difficult!),
  • • how attractive do people think it is,
  • • to what extent is it useful to people,
  • • how endangered is it,
  • • how big is it,
  • • how aware are people of it?


The value of a life is negatively impacted by the following factors:-

  • • how much it hurts people,
  • • is it a parasite on people,
  • • is it a parasite on a pet or livestock animal,
  • • is it a parasite on something we can empathise with,
  • • how much does it eat our food,
  • • to what extent does it get in the way of us creating our food,
  • • how much does it damage wildlife, gardens, the environment or human endeavour,
  • • does it look ugly or scary,
  • • is it an alien to the ecosystem it is in,
  • • is it related to species that are impacted by the above concerns (prejudice),
  • • is it extremely abundant?


In practice laws are there to underpin morality and in the case of the value of animal lives the law generally applies the following levels of discernment:-

  1. 1) Human, vertebrate or invertebrate

This is the basic fundamental three-way split.

Should you be so fortunate to be a species of Homo sapiens, you will find that most legal systems place a very high value on your life, and indeed your health and welfare.  Not only is the legislation around human lives very mature and robust, the language sets apart the unwarranted taking of a human life from the taking of all other animal lives – it is a murder.  Your protection is not quite universal, there are places on the planet where it is possible to behave so badly that the state will take a decision to remove your life, and other situations, which if persistent we call ‘war’, where the value of your life may fall below the value of other objectives.

Even if not a human, if you are a member of the Phylum Chordata and also happen to have a backbone (i.e. you are a vertebrate) then your life, and indeed welfare, qualifies for a much higher level of value in the eyes of the law than if you are a member of the Phylum Chordata without a backbone, or a species representing any of the other 34 Phyla of animals (i.e. you are an invertebrate). There are some gradients within the vertebrate category with fish often being given less protection than mammals.

  1. 2) Invasive non-native or not

If you are not supposed to be present in an ecosystem your life will often be given a lower value by law, although humans have special delicate rules in this regard, and generally vertebrates are still treated with a deal more respect than invertebrates.  If, as well as being an alien, you are also causing damage you may find yourself on an extermination list!

  1.   3) Endangered or not

Should you be a member of an endangered species you are much more likely to be protected by legislation, sometimes Governments are also required to licence and/or monitor killing.  You are more likely to make it onto the list if you can be big and make yourself known to humans, and it is a very good idea to be nice and fluffy with big eyes.

  1. 4) Owned or not owned

If you are owned by a human your life will sometimes have a higher level of protection then if you are wild – I don’t mean to put you down, but in truth this is more a reflection of the importance the law confers on ownership than actually the value of your life.


There is more to the ethics of taking a life than simply the value of that life.  Motivation, intention and purpose are of huge significance as well.  That will be the subject of the next blog in this series.

Of course people do differ wildly in how much they value life.  I remember a little girl, watching her father delicately removing a head louse from her hair and carefully depositing it into a glass full of meths, peer mournfully over her shoulder and say quietly “I feel sorry for them”.